KR20230112427A - Method and apparatus for transmitting a uplink data channel in wireless communication system - Google Patents

Abstract

The present disclosure relates to a 5G or 6G communication system to support a higher data transmission rate. The present disclosure relates to a communication technique and system that integrates a 5G communication system with IoT technology to support a higher data transmission rate after a 4G system. The present disclosure can be applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology. According to various embodiments of the present disclosure, a method performed by a base station in a wireless communication system includes the steps of: receiving, from a terminal, terminal capability report information; transmitting an upper layer parameter determined based on the terminal capability report information to the terminal; receiving, from the terminal, a sounding reference signal (SRS) determined by the upper layer parameter; determining downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH) based on the SRS; transmitting a signal including the DCI to the terminal; and receiving the PUSCH and uplink (UL) phase tracking reference signal (PTRS) from the terminal.

Description

Method and apparatus for transmitting uplink data channel in wireless communication system {METHOD AND APPARATUS FOR TRANSMITTING A UPLINK DATA CHANNEL IN WIRELESS COMMUNICATION SYSTEM}

The present disclosure relates to the operation of a terminal and a base station in a wireless communication system. Specifically, the present disclosure relates to a method and apparatus for determining precoding for transmitting an uplink data channel by a terminal in a wireless communication system and configuring a phase tracking reference signal (PTRS) for phase error correction.

5G mobile communication technology defines a wide frequency band to enable fast transmission speed and new services, and can be implemented in sub-6GHz frequency bands such as 3.5GHz (3.5GHz) as well as ultra-high frequency bands called mmWave such as 28GHz and 39GHz ('Above 6GHz'). In addition, in the case of 6G mobile communication technology, which is called a system after 5G communication (Beyond 5G), in order to achieve transmission speed that is 50 times faster than 5G mobile communication technology and ultra low latency reduced to 1/10, implementation in a Terahertz band (eg, 3 THz band at 95 GHz) is being considered.

In the early days of 5G mobile communication technology, with the goal of satisfying service support and performance requirements for enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), beamforming and massive array multiple I/O ( Massive MIMO), various numerology support for efficient use of ultra-high frequency resources (multiple subcarrier spacing operation, etc.) and dynamic operation for slot formats, initial access technology to support multi-beam transmission and broadband, definition and operation of BWP (Band-Width Part), LDPC (Low Density Parity Check) code for large-capacity data transmission and new channel coding methods such as polar code for reliable transmission of control information, L2 pre-processing (L2 Standardization has progressed for pre-processing, network slicing that provides a dedicated network specialized for a specific service, and the like.

Currently, discussions are underway to improve and enhance performance of the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support. V2X (Vehicle-to-Everything) to help autonomous vehicle driving decisions based on its own location and status information transmitted by the vehicle and increase user convenience, NR-U (New Radio Unlicensed) for the purpose of system operation that meets various regulatory requirements in unlicensed bands, Physical layer standardization is in progress for technologies such as NR UE Power Saving, Non-Terrestrial Network (NTN), which is UE-satellite direct communication to secure coverage in areas where communication with terrestrial networks is impossible, and positioning.

In addition, Industrial Internet of Things (IIoT) for new service support through linkage and convergence with other industries, IAB (Integrated Access and Backhaul) that provides nodes for network service area expansion by integrating and supporting wireless backhaul links and access links, mobility enhancement technology including conditional handover and DAPS (Dual Active Protocol Stack) handover, 2-step random access that simplifies random access procedures Standardization of air interface architecture/protocol for technologies such as ACH for NR) is also in progress, and 5G 　baseline architecture (e.g., Service based Architecture, Service based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, standardization in system architecture/service fields for mobile edge computing (MEC), etc., which provides services based on the location of the terminal In progress.

When such a 5G mobile communication system is commercialized, the explosively increasing number of connected devices will be connected to the communication network, and accordingly, it is expected that the function and performance enhancement of the 5G mobile communication system and the integrated operation of connected devices will be required. To this end, new research will be conducted on 5G performance improvement and complexity reduction using eXtended Reality (XR), Artificial Intelligence (AI) and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR), AI service support, Metaverse service support, and drone communication.

In addition, the development of such a 5G mobile communication system is a new waveform for guaranteeing coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technology such as full dimensional MIMO (FD-MIMO), array antenna, and large scale antenna, high-dimensional space using metamaterial-based lenses and antennas, and Orbital Angular Momentum (OAM) to improve coverage of terahertz band signals In addition to multiplexing technology and RIS (Reconfigurable Intelligent Surface) technology, full duplex technology to improve frequency efficiency and system network of 6G mobile communication technology, satellite, and AI (Artificial Intelligence) are utilized from the design stage, and end-to-end AI support functions are internalized to realize system optimization. Next-generation distribution that realizes complex services that exceed the limits of terminal computing capabilities using ultra-high-performance communication and computing resources. It can be a basis for the development of computing technology, etc.

As described above, as various services can be provided according to the development of wireless communication systems, there is a need for a method for providing these services more smoothly. In particular, a method for determining precoding for efficiently transmitting an uplink data channel and constructing a phase tracking reference signal for phase error correction is required.

Various embodiments of the present disclosure are intended to provide an apparatus and method capable of effectively providing a service in a wireless communication system.

According to embodiments of the present disclosure, a method performed by a base station in a wireless communication system includes receiving UE capability report information from a UE, transmitting a higher layer parameter determined based on the UE capability report information including information on coherency between antennas of the UE to the UE, receiving a sounding reference signal (SRS) determined by the higher layer parameter from the UE, scheduling a physical uplink shared channel (PUSCH) based on the SRS, It may include determining downlink control information (DCI), transmitting the DCI to the terminal, and receiving the PUSCH and uplink (UL) phase tracking reference signal (PTRS) from the terminal.

According to embodiments of the present disclosure, a method performed by a UE in a wireless communication system includes transmitting UE capability report information to a base station, receiving a higher layer parameter determined based on the UE capability report information including information on coherency between antennas of the UE from the base station, transmitting a sounding reference signal (SRS) determined by the higher layer parameter to the base station, scheduling a physical uplink shared channel (PUSCH) determined based on the SRS receiving downlink control information (DCI) from the base station, and transmitting the PUSCH and uplink (UL) phase tracking reference signal (PTRS) to the base station.

According to embodiments of the present disclosure, in a wireless communication system, a base station device receives UE capability report information from a UE, transmits higher layer parameters determined based on the UE capability report information including information on coherency between antennas of the UE to the UE, receives a sounding reference signal (SRS) determined by the higher layer parameter from the UE, and schedules a physical uplink shared channel (PUSCH) based on the SRS. ), transmit the DCI to the terminal, and receive the PUSCH and uplink (UL) phase tracking reference signal (PTRS) from the terminal.

According to embodiments of the present disclosure, in a wireless communication system, a terminal device transmits UE capability report information to a base station, receives a higher layer parameter determined based on the UE capability report information including information on coherency between antennas of the UE from the base station, and transmits a sounding reference signal (SRS) determined by the higher layer parameter to the base station, and schedules a physical uplink shared channel (PUSCH) determined based on the SRS. information) from the base station, and may include a processor configured to transmit the PUSCH and uplink (UL) phase tracking reference signal (PTRS) to the base station.

According to various embodiments of the present disclosure, an apparatus and method capable of effectively providing a service in a wireless communication system are provided.

1 illustrates a basic structure of a time-frequency domain in a wireless communication system according to an embodiment of the present disclosure.
2 illustrates structures of frames, subframes, and slots in a wireless communication system according to an embodiment of the present disclosure.
3 illustrates an example of setting a bandwidth portion in a wireless communication system according to an embodiment of the present disclosure.
4 illustrates an example of setting a control resource set of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure.
5 illustrates a structure of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure.
6 illustrates an example in which a terminal may have a plurality of PDCCH monitoring positions in a slot through Span in a wireless communication system according to an embodiment of the present disclosure.
7 illustrates an example in which a base station allocates a beam according to TCI state setting in a wireless communication system according to an embodiment of the present disclosure.
8 illustrates an example of a TCI state allocation method for a PDCCH in a wireless communication system according to an embodiment of the present disclosure.
9 illustrates a TCI indication MAC CE signaling structure for PDCCH DMRS in a wireless communication system according to an embodiment of the present disclosure.
10 illustrates beam configuration of a control resource set and a search space in a wireless communication system according to an embodiment of the present disclosure.
11 illustrates an example of a method for selecting a receivable control resource set in consideration of priority when a terminal receives a downlink control channel in a wireless communication system according to an embodiment of the present disclosure.
12 illustrates frequency axis resource allocation of a PDSCH in a wireless communication system according to an embodiment of the present disclosure.
13 illustrates time axis resource allocation of a PDSCH in a wireless communication system according to an embodiment of the present disclosure.
14 illustrates time axis resource allocation according to subcarrier intervals of a data channel and a control channel in a wireless communication system according to an embodiment of the present disclosure.
15 illustrates PUSCH repeated transmission type B in a wireless communication system according to an embodiment of the present disclosure.
16 illustrates a radio protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation in a wireless communication system according to an embodiment of the present disclosure.
17 illustrates an operation flow of a base station for configuring a PTRS and determining precoding based on a capability report of a terminal according to an embodiment of the present disclosure.
18 illustrates an operation flow of a terminal for configuring a PTRS and determining precoding based on a capability report of the terminal according to an embodiment of the present disclosure.
19 illustrates a configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure.
20 illustrates a configuration of a base station in a wireless communication system according to an embodiment of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In describing the embodiments of the present disclosure, descriptions of technical contents that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to more clearly convey the gist of the present disclosure without obscuring it by omitting unnecessary description. For the same reason, in the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated. Also, the size of each component does not entirely reflect the actual size. In each figure, the same reference number is given to the same or corresponding component.

Advantages and features of the present disclosure, and methods of achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in a variety of different forms. Embodiments of the present disclosure are provided to make the disclosure of the present disclosure complete, and to fully inform those skilled in the art of the scope of the disclosure to which the present disclosure belongs, and the present disclosure is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification. In addition, in describing the present disclosure, if it is determined that a detailed description of a related function or configuration may unnecessarily obscure the subject matter of the present disclosure, the detailed description will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present disclosure, which may vary according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout this specification.

Hereinafter, the base station is a subject that performs resource allocation of the terminal, and may be at least one of gNode B, gNB, eNode B, eNB, Node B, base station (BS), radio access unit, base station controller, or node on the network. In addition, the base station may support an integrated access and backhaul-donor (IAB-donor), which is a gNB that provides network access to the terminal (s) through a network of backhaul and access links in the NR system, and NR access link (s) to the terminal (s). A base station may be a network entity comprising at least one of an IAB-node, which is a radio access network (RAN) node supporting NR backhaul links to the IAB-donor or another IAB-node. The terminal is wirelessly connected through the IAB-node and can transmit and receive data with an IAB-donor connected to at least one IAB-node through a backhaul link. A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing communication functions. In the present disclosure, downlink (DL) may be a wireless transmission path of a signal transmitted from a base station to a terminal. Uplink (UL) means a radio transmission path of a signal transmitted from a terminal to a base station. In addition, although an LTE or LTE-A system may be described below as an example, embodiments of the present disclosure may be applied to other communication systems having a similar technical background or channel type. For example, the ^5th generation (5G) wireless communication technology (new radio, NR) developed after LTE-A may be included in this, and the following 5G may be a concept including existing LTE, LTE-A and other similar services. In addition, the present disclosure can be applied to other communication systems through some modifications within a range that does not greatly deviate from the scope of the present disclosure as determined by those skilled in the art. Various embodiments of the present disclosure may be applied in frequency division duplex (FDD) or time division duplex (TDD).

At this time, it will be understood that each block of the process flow chart diagrams and combinations of the flow chart diagrams can be performed by computer program instructions. Computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer or other programmable data processing equipment. Those instructions executed by a processor of a computer or other programmable data processing equipment will create means for performing the functions described in the flowchart block(s). Computer program instructions may be stored in computer usable or computer readable memory that may direct a computer or other programmable data processing equipment to implement functionality in a particular way. Instructions stored in computer usable or computer readable memory may produce an article of manufacture containing instruction means that performs the functions described in the flowchart block(s). Computer program instructions can be embodied on a computer or other programmable data processing equipment. Instructions performed on a computer or other programmable data processing equipment may provide steps for performing the functions described in the flowchart block(s) by performing a series of operational steps on the computer or other programmable data processing equipment to create a computer-executed process.

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). Also, in some alternative implementations, it is possible for the functions mentioned in the blocks to occur out of order. For example, two blocks shown in succession may in fact be performed substantially concurrently, or the blocks may sometimes be performed in reverse order depending on their function.

At this time, the term '~unit' used in this embodiment may mean software or a hardware component such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), and '~unit' may perform certain roles. However, '~ part' is not limited to software or hardware. '~bu' may be configured to be in an addressable storage medium and may be configured to reproduce one or more processors. Thus, as an example, '~unit' may include software components, object-oriented software components, components such as class components and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. Functions provided within components and '~units' may be combined into smaller numbers of components and '~units' or further separated into additional components and '~units'. Components and '~units' may be implemented to play one or more CPUs in a device or a secure multimedia card. Also, in various embodiments of the present disclosure, '~ unit' may include one or more processors. Hereinafter, in describing the present disclosure, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present disclosure, the detailed description may be omitted. Hereinafter, various embodiments of the present disclosure will be described with reference to the accompanying drawings.

The wireless communication system has moved away from providing voice-oriented services in the early days, and is capable of providing high-speed, high-quality packet data, such as communication standards such as 3GPP's high speed packet access (HSPA), LTE (long term evolution or E-UTRA (evolved universal terrestrial radio access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's high rate packet data (HRPD), UMB (ultra mobile broadband), and IEEE's 802.16e. It is developing into a broadband wireless communication system that provides services.

As a representative example of a broadband wireless communication system, an LTE system adopts an orthogonal frequency division multiplexing (OFDM) method in downlink and adopts a single carrier frequency division multiple access (SC-FDMA) method in uplink. Uplink may refer to a radio link in which a user equipment (UE) or a mobile station (MS) transmits data or a control signal to a base station (eNode B or base station (BS)). Downlink may refer to a radio link through which a base station transmits data or a control signal to a terminal. In the above-described multiple access method, data or control information of each user can be distinguished by assigning and operating time-frequency resources to carry data or control information for each user so that they do not overlap each other, that is, to establish orthogonality.

As a future communication system after LTE, the 5G communication system must be able to freely reflect various requirements of users and service providers, so services that satisfy various requirements at the same time must be supported. Services considered for the 5G communication system include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra reliability low latency communication (URLLC).

eMBB aims to provide a data transmission rate that is more improved than that supported by existing LTE, LTE-A or LTE-Pro. For example, in a 5G communication system, an eMBB must be able to provide a peak data rate of 20 Gbps in downlink and a peak data rate of 10 Gbps in uplink from the perspective of one base station. In addition, the 5G communication system should provide an increased user perceived data rate while providing an improved maximum transmission rate. In order to satisfy these requirements, various transmission/reception technologies are required to be improved, including a more advanced multi-input multi-output (MIMO) transmission technology. In addition, while signals are transmitted using a transmission bandwidth of up to 20 MHz in the 2 GHz band used by LTE, the 5G communication system uses a frequency bandwidth wider than 20 MHz in a frequency band of 3 to 6 GHz or 6 GHz or higher, thereby satisfying the data transmission rate required by the 5G communication system.

At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. In order to efficiently provide the Internet of Things, mMTC requires access support for large-scale terminals within a cell, improved coverage of terminals, improved battery time, and reduced terminal cost. Since the IoT is attached to various sensors and various devices to provide a communication function, it must be able to support a large number of terminals (eg, 1,000,000 terminals/km ² ) in a cell. In addition, due to the nature of the service, terminals supporting mMTC are likely to be located in shadow areas that are not covered by cells, such as the basement of a building, so a wider coverage than other services provided by the 5G communication system may be required. A terminal supporting mMTC must be composed of a low-cost terminal, and since it is difficult to frequently replace a battery of the terminal, a very long battery life time such as 10 to 15 years may be required.

In the case of URLLC, it is a cellular-based wireless communication service used for a specific purpose (mission-critical). For example, services used for remote control of robots or machinery, industrial automation, unmaned aerial vehicles, remote health care, and emergency alerts may be considered. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds (ms), and at the same time, a packet error rate of 10 ^-5 or less may be required. Therefore, for a service that supports URLLC, the 5G system must provide a smaller transmit time interval (TTI) than other services, and at the same time allocate wide resources in the frequency band to secure the reliability of the communication link. Design requirements may be required.

The three services of 5G, namely eMBB, URLLC, and mMTC, can be multiplexed and transmitted in one system. At this time, different transmission/reception techniques and transmission/reception parameters may be used between services in order to satisfy different requirements of each service. Of course, 5G is not limited to the three services mentioned above.

For convenience of description below, some terms and names defined in the 3GPP standards (5G, NR, LTE, or similar system standards) may be used. However, the present disclosure is not limited by terms and names, and may be equally applied to systems conforming to other standards. In addition, terms used in the following description for identifying connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, and various types of identification information are illustrated for convenience of description. Therefore, it is not limited to the terms used in this disclosure, and other terms that refer to objects having equivalent technical meanings may be used.

An embodiment of the present disclosure is to provide a method and apparatus for efficiently transmitting an uplink data channel to a terminal supporting a plurality of uplink transmission antennas in a wireless communication system. For example, it is possible to provide a method and apparatus for efficiently transmitting an uplink data channel for a terminal supporting eight uplink transmission antennas, and a method and apparatus for efficiently transmitting an uplink data channel for a terminal supporting more or fewer uplink transmission antennas.

In addition, according to an embodiment of the present disclosure, in a wireless communication system, a terminal can perform precoding for uplink data channel transmission using a plurality of uplink transmission antennas, and a phase tracking reference signal (PTRS) for phase tracking. An apparatus and method capable of associating a demodulation reference signal (DMRS) without ambiguity are provided. For example, it is possible to perform precoding for uplink data channel transmission using eight uplink transmission antennas, provide an apparatus and method capable of associating a phase tracking reference signal (PTRS) for phase tracking with a demodulation reference signal (DMRS) without ambiguity, precoding for uplink data channel transmission using more or fewer uplink transmission antennas, and phase tracking reference signal (PTRS) for phase tracking DMRS without ambiguity. An apparatus and method capable of association with a demodulation reference signal (RS) may be provided.

[NR time-frequency resource]

Hereinafter, the frame structure of the 5G system will be described in more detail with reference to the drawings.

1 illustrates a basic structure of a time-frequency domain in a wireless communication system according to an embodiment of the present disclosure. Specifically, FIG. 1 shows a basic structure of a time-frequency domain, which is a radio resource domain in which data or control channels are transmitted in a 5G system.

1, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE) 101, one orthogonal frequency division multiplexing (OFDM) symbol 102 on the time axis and one subcarrier on the frequency axis. It can be defined as 103. in the frequency domain (eg, 12) consecutive REs may constitute one resource block (RB) 104 . Referring to Figure 1, Is the number of OFDM symbols per subframe 110 for setting the subcarrier interval (μ). For a more detailed description of the resource structure in the 5G system, refer to TS 38.211 section 4 standard.

2 illustrates structures of frames, subframes, and slots in a wireless communication system according to an embodiment of the present disclosure. Specifically, FIG. 2 shows an example of a structure of a frame 200 , a subframe 201 , and a slot 202 .

One frame 200 may be defined as 10 ms. One subframe 201 may be defined as 1 ms. Accordingly, one frame 200 may include a total of 10 subframes 201 . One slot (202, 203) may be defined as 14 OFDM symbols (eg, the number of symbols per slot ( ) may be 14). One subframe 201 may consist of one or a plurality of slots 202 and 203. The number of slots 202 and 203 per one subframe 201 may vary according to the set value μ(204, 205) for the subcarrier interval. Referring to FIG. 2 , according to an exemplary embodiment, a case 204 when μ=0 and a case 205 when μ=1 are illustrated as subcarrier interval setting values. When μ=0 (204), one subframe 201 may consist of one slot 202. When μ=1 (205), one subframe 201 may consist of two slots 203. That is, the number of slots per 1 subframe according to the setting value μ for the subcarrier spacing ( ) may vary. The number of slots per frame according to the setting value μ for the subcarrier interval ( ) may vary. According to each subcarrier spacing setting μ and Can be defined as shown in Table 1.

[Bandwidth Part (BWP)]

Next, the bandwidth part (BWP) setting in the 5G communication system will be described in detail with reference to the drawings.

3 illustrates an example of setting a bandwidth portion in a wireless communication system according to an embodiment of the present disclosure. Specifically, referring to FIG. 3, an example in which the UE bandwidth 300 is set to two bandwidth parts (ie, bandwidth part # 1 (BWP # 1) 301 and bandwidth part # 2 (BWP # 2) 302) is shown.

The base station may set one or a plurality of bandwidth parts to the terminal. The base station may set various pieces of information for each bandwidth part, as shown in Table 2 below.

Referring to Table 2, 'locationAndBandwidth' represents the location and bandwidth of the corresponding bandwidth part in the frequency domain. 'subcarrierSpacing' indicates the subcarrier spacing to be used in the corresponding bandwidth part. 'cyclicPrefix' indicates whether an extended cyclic prefix (CP) is used for a corresponding bandwidth part.

According to an embodiment of the present disclosure, settings related to the bandwidth part are not limited to Table 2, and various parameters related to the bandwidth part may be set to the terminal in addition to the setting information in Table 2. The base station may deliver configuration information to the terminal through higher layer signaling (eg, radio resource control (RRC) signaling). At least one bandwidth part among one or a plurality of set bandwidth parts may be activated. The base station may semi-statically transmit whether or not the set bandwidth part is activated to the terminal through RRC signaling. The base station may dynamically transmit whether or not the bandwidth portion set to the terminal is activated through downlink control information (DCI).

According to an embodiment of the present disclosure, a terminal before RRC connection may receive an initial bandwidth portion (initial BWP) for initial access from a base station through a master information block (MIB). More specifically, the terminal can transmit a control resource set (CORESET) to which a PDCCH for receiving system information (e.g., remaining system information (RMSI) or system information block 1 (SIB1)) required for initial access in the initial access step can be received through the MIB. In addition, the terminal may receive configuration information on a search space through the MIB. The identity (ID) of the control resource set and the search space set by the MIB can be regarded as 0, respectively. The control resource set and search space set through the MIB may be referred to as a common control resource set and common search space, respectively. The base station may notify the terminal of setting information such as frequency allocation information, time allocation information, and numerology for the control region #0 through the MIB. In addition, the base station may notify the terminal of setting information on the monitoring period and occasion for the control region #0 (ie, setting information for the search space #0) through the MIB. The terminal may regard the frequency domain set as the control resource set #0 acquired from the MIB as an initial bandwidth part for initial access. At this time, the identifier (ID) of the initial bandwidth part may be regarded as 0. A control resource set may be referred to as a control region, a control resource region, and the like.

According to various embodiments of the present disclosure, setting for a portion of a bandwidth supported by 5G may be used for various purposes.

According to an embodiment, when the bandwidth supported by the terminal is smaller than the system bandwidth, the base station may support data transmission and reception of the terminal through the setting of the bandwidth portion. For example, the base station can set the frequency position of the bandwidth part to the terminal, and the terminal can transmit and receive data at a specific frequency position within the system bandwidth.

Also, according to an embodiment, the base station may set a plurality of bandwidth parts to the terminal for the purpose of supporting different numerologies. For example, the base station may set the two bandwidth parts to subcarrier spacings of 15 kHz and 30 kHz, respectively, in order to support both data transmission and reception using subcarrier spacing of 15 kHz and subcarrier spacing of 30 kHz. Different bandwidth parts may be frequency division multiplexed (FDD). When the terminal wants to transmit/receive data at a specific subcarrier interval, a bandwidth part set at a specific subcarrier interval can be activated.

Also, according to an embodiment, the base station may set bandwidth parts having different sizes of bandwidths to the terminal for the purpose of reducing power consumption of the terminal. For example, when a terminal supports a very large bandwidth (eg, a bandwidth of 100 MHz) and always transmits/receives data with the corresponding bandwidth, very large power consumption may occur. In particular, monitoring an unnecessary downlink control channel with a large bandwidth of 100 MHz in a non-traffic situation may be very inefficient in terms of power consumption. For the purpose of reducing power consumption of the terminal, the base station may set a relatively small bandwidth portion (eg, a bandwidth portion of 20 MHz) to the terminal. In a situation where there is no traffic, the terminal can perform a monitoring operation in the 20 MHz bandwidth part, and when data is generated, it can transmit and receive data in the 100 MHz bandwidth part according to the instructions of the base station.

In the method for setting the bandwidth part, terminals before RRC connection (connected) may receive setting information on the initial bandwidth part (initial bandwidth part) through a master information block (MIB) in an initial access step. More specifically, the terminal may receive a control resource set (CORESET) set from the MIB of a physical broadcast channel (PBCH). The control resource set configured by the terminal may be a control resource set for a downlink control channel through which downlink control information (DCI) scheduling a system information block (SIB) may be transmitted. The bandwidth of the control resource set set by the MIB can be regarded as an initial bandwidth part. Through the set initial bandwidth portion, the terminal can receive a physical downlink shared channel (PDSCH) through which the SIB is transmitted. The initial bandwidth portion may be used for other system information (OSI), paging, and random access in addition to the purpose of receiving the SIB.

[Bandwidth Part (BWP) change]

When one or more bandwidth parts are configured for the terminal, the base station may instruct the terminal to change (switching or transition) the bandwidth part using a bandwidth part indicator field in the DCI.

3 illustrates an example of setting a bandwidth portion in a wireless communication system according to an embodiment of the present disclosure. Referring to FIG. 3, when the currently activated bandwidth part is bandwidth part #1 (301), the base station may indicate bandwidth part #2 (302) to the terminal as a bandwidth part indicator in the DCI. Upon receiving the DCI including the bandwidth portion indicator, the terminal may change the bandwidth portion to the bandwidth portion #2 302 indicated by the bandwidth portion indicator.

As described above, the change of the bandwidth portion performed based on the DCI may be indicated by the DCI scheduling the PDSCH or the PUSCH. Upon receiving a request for changing the bandwidth portion, the UE must be able to receive or transmit the PDSCH or PUSCH scheduled by the corresponding DCI without difficulty in the changed bandwidth portion. To this end, the standard specifies requirements for a delay time (T _BWP ) required when changing a bandwidth part. Requirements for delay time (T _BWP ) may be defined as shown in Table 3 below, but are not limited thereto.

The requirement for the bandwidth portion change delay time may support type 1 or type 2 according to the capability of the terminal. The terminal may report the supportable bandwidth partial delay time type to the base station.

According to the above-described requirement for the bandwidth portion change delay time, when the terminal receives the DCI including the bandwidth portion change indicator in slot n, the terminal changes to the new bandwidth portion indicated by the bandwidth portion change indicator at slot n + T It can be completed at a time not later than _BWP . Through this, the UE can transmit and receive data channels scheduled by the corresponding DCI in the changed new bandwidth portion. When the base station wishes to schedule a data channel with a new bandwidth part, it can determine time domain resource allocation for the data channel by considering the bandwidth part change delay time (T _BWP ) of the terminal. That is, when scheduling a data channel with a new bandwidth part, in the method of determining time domain resource allocation for the data channel, the base station may schedule the corresponding data channel after the bandwidth part change delay time. Accordingly, the terminal may not expect that the DCI indicating the bandwidth portion change indicates a slot offset value (K0 or K2) smaller than the bandwidth portion change delay time (T _BWP ).

If the terminal receives a DCI (e.g., DCI format 1_1 or 0_1) indicating a change in bandwidth portion, the terminal may not perform any transmission or reception during the time interval from the third symbol of the slot in which the PDCCH including the DCI is received to the start point of the slot indicated by the slot offset (K0 or K2) value indicated by the time domain resource allocation indicator field included in the corresponding DCI. For example, if the terminal receives a DCI indicating a bandwidth portion change in slot n, and the slot offset value indicated by the corresponding DCI is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol preceding slot n + K (i.e., the last symbol of slot n + K-1).

[SS/PBCH block]

Next, a synchronization signal (SS)/PBCH block in 5G will be described. The SS/PBCH block may mean a physical layer channel block composed of a primary SS (PSS), a secondary SS (SSS), and a PBCH. Specifically, the functions of PSS, SSS, and PBCH are as described below.

- PSS: A signal that is a reference signal for downlink time/frequency synchronization, and may provide some information of cell ID.

- SSS: serves as a standard for downlink time/frequency synchronization, and provides remaining cell ID information not provided by PSS. Additionally, the SSS may serve as a reference signal for demodulation of the PBCH.

- PBCH: It can provide essential system information necessary for transmitting and receiving the data channel and control channel of the terminal. Essential system information may include search space-related control information indicating radio resource mapping information of a control channel, scheduling control information for a separate data channel through which system information is transmitted, and the like.

- SS/PBCH block: The SS/PBCH block may be a combination of PSS, SSS, and PBCH. One or a plurality of SS/PBCH blocks may be transmitted within 5 ms, and each SS/PBCH block to be transmitted may be distinguished by an index.

The UE can detect the PSS and SSS in the initial access stage and decode the PBCH. The UE may obtain the MIB from the PBCH, and may receive a control resource set (CORESET) #0 (eg, a control resource set having a control resource set index of 0) set from the MIB. The UE may perform monitoring for the control resource set #0 assuming that the selected SS/PBCH block and demodulation reference signal (DMRS) transmitted in the control resource set #0 are quasi co location (QCL). The terminal may receive system information through downlink control information transmitted from control resource set #0. The terminal may obtain random access channel (RACH)-related configuration information required for initial access from the received system information. The terminal may transmit a physical RACH (PRACH) to the base station in consideration of the selected SS/PBCH index. The base station receiving the PRACH can obtain information about the SS/PBCH block index selected by the terminal. The base station can know which block the terminal has selected among each of the SS/PBCH blocks. The base station can know that the terminal has monitored the control resource set #0 associated with the selected SS/PBCH block.

[PDCCH: DCI related]

Next, downlink control information (DCI) in the 5G system will be described in detail.

Scheduling information for uplink data (or physical uplink shared channel (PUSCH)) or downlink data (or physical downlink shared channel (PDSCH)) in the 5G system is via DCI. It can be transmitted from the base station to the terminal. The UE may monitor the DCI format for fallback and the DCI format for non-fallback with respect to PUSCH or PDSCH. The contingency DCI format may be composed of a fixed field predefined between the base station and the terminal, and the DCI format for non-preparation may include a configurable field.

DCI may be transmitted through a physical downlink control channel (PDCCH) through channel coding and modulation processes. A cyclic redundancy check (CRC) may be attached to a DCI message payload. The CRC may be scrambled with a radio network temporary identifier (RNTI) corresponding to the identity of the terminal. Different RNTIs may be used according to the purpose of the DCI message (eg, UE-specific data transmission, power control command or random access response, etc.). That is, the RNTI may be included in the CRC calculation process and transmitted without being explicitly transmitted. The UE may receive the DCI message transmitted on the PDCCH. The UE can check the CRC using the allocated RNTI included in the received DCI message. The terminal can know that the corresponding message has been transmitted to the terminal based on the CRC check result.

According to an embodiment, a DCI scheduling a PDSCH for system information (SI) may be scrambled with an SI-RNTI. A DCI for scheduling a PDSCH for a random access response (RAR) message may be scrambled with RA-RNTI. DCI scheduling PDSCH for paging messages may be scrambled with P-RNTI. DCI notifying SFI (slot format indicator) may be scrambled with SFI-RNTI. DCI notifying transmit power control (TPC) may be scrambled with TPC-RNTI. A DCI scheduling a UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (cell RNTI). According to an embodiment, the P-RNTI and the SI-RNTI may be common RNTIs that are not allocated to a specific UE but are commonly allocated to all UEs within a cell.

DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, and in this case, CRC can be scrambled with C-RNTI. For example, DCI format 0_0 in which the CRC is scrambled with C-RNTI may include information described in Table 4 below. However, according to an embodiment, information included in DCI format 0_0 in which CRC is scrambled with C-RNTI is not limited to Table 4.

DCI format 0_1 can be used as a non-backup DCI for scheduling PUSCH, and in this case, CRC can be scrambled with C-RNTI. For example, DCI format 0_1 in which the CRC is scrambled with C-RNTI may include information described in Table 5 below. However, according to an embodiment, information included in DCI format 0_1 in which CRC is scrambled with C-RNTI is not limited to Table 5.

DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, and in this case, CRC can be scrambled with C-RNTI. For example, DCI format 1_0 in which the CRC is scrambled with C-RNTI may include information described in Table 6 below. However, according to one embodiment, information included in DCI format 1_0 in which CRC is scrambled with C-RNTI is not limited to Table 6.

DCI format 1_1 can be used as a non-backup DCI for scheduling PDSCH, and in this case, CRC can be scrambled with C-RNTI. For example, DCI format 1_1 in which the CRC is scrambled with C-RNTI may include information described in Table 7 below. However, according to one embodiment, information included in DCI format 1_1 in which CRC is scrambled with C-RNTI is not limited to Table 7.

[PDCCH: CORESET, REG, CCE, Search Space]

In the following, a downlink control channel in a 5G communication system will be described in more detail with reference to the drawings.

4 illustrates an example of setting a control resource set of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure. More specifically, referring to FIG. 4, an example of a control resource set through which a downlink control channel is transmitted in a 5G wireless communication system is shown. Referring to FIG. 4, an example in which two control resource sets (control resource set # 1 (401) and control resource set # 2 (402)) is set in a UE bandwidth part 410 on the frequency axis and one slot 420 on the time axis is shown. The control resource sets 401 and 402 may be set to a specific frequency resource 403 within the entire terminal bandwidth portion 410 on the frequency axis. In FIG. 4, a specific frequency resource 403 shows an example of a frequency resource set in the control resource set #1 401. The control resource set may be set to one or a plurality of OFDM symbols on the time axis, and this may be defined as a control resource set duration (404). Referring to FIG. 4, according to an embodiment, control resource set #1 (401) is set to a control resource set length of two symbols, and control resource set #2 (402) is set to a control resource set length of one symbol.

The above-described control resource set in 5G may be configured through higher layer signaling (eg, system information, MIB, RRC signaling) transmitted from the base station to the terminal. Setting a control resource set to the terminal may be understood as providing information such as a control resource set identifier, a frequency location of the control resource set, and a symbol length of the control resource set to the terminal. For example, the setting information for the control resource set may include information listed in Table 8.

In Table 8, the tci-StatesPDCCH (i.e., transmission configuration indication (TCI) state) configuration information may include one or more SS/PBCH block indexes or channel state information reference signal (CSI-RS) index information in a quasi co located (QCL) relationship with a DMRS transmitted from a corresponding control resource set.

5 illustrates a structure of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure. Referring to FIG. 5, an example of a basic unit of time and frequency resources constituting a downlink control channel that can be used in 5G is shown. According to FIG. 5, a basic unit of time and frequency resources constituting a control channel may be referred to as a resource element group (REG) 503, and the REG 503 may be defined as 1 OFDM symbol 501 on the time axis and 1 physical resource block (PRB) 502 on the frequency axis, that is, 12 subcarriers. The base station may concatenate one or more REGs 503 to form a downlink control channel allocation unit.

As shown in FIG. 5, when a basic unit to which a downlink control channel is allocated in 5G is a control channel element (CCE) 504, one CCE 504 may include a plurality of REGs 503. Referring to the REG 503 shown in FIG. 5, the REG 503 may consist of 12 REs. If 1 CCE 504 consists of 6 REGs 503, 1 CCE 504 may consist of 72 REs. When a downlink control resource set is set, a corresponding area may be composed of a plurality of CCEs 504. A specific downlink control channel may be mapped to one or a plurality of CCEs 504 according to an aggregation level (AL) in the control resource set and transmitted. CCEs 504 in the control resource set may be identified by number. The number of CCEs 504 may be assigned according to a logical mapping method.

The basic unit (ie, REG 503) of the downlink control channel shown in FIG. 5 may include both REs to which DCI is mapped and a region to which the DMRS 505, which is a reference signal for decoding them, is mapped. Referring to FIG. 5, three DMRSs 505 can be transmitted in one REG 503. The number of CCEs required to transmit the PDCCH may be 1, 2, 4, 8, or 16 according to the aggregation level (AL). Different numbers of CCEs may be used to implement link adaptation of a downlink control channel. For example, when AL=L, one downlink control channel can be transmitted through L CCEs. The UE needs to detect a signal without knowing information about the downlink control channel. Accordingly, a search space representing a set of CCEs may be defined for blind decoding. The search space may be a set of downlink control channel candidates consisting of CCEs that the UE should attempt to decode on a given aggregation level. Since there are various aggregation levels that make one bundle with 1, 2, 4, 8, or 16 CCEs, the terminal can have multiple search spaces. A search space set may be defined as a set of search spaces at all set aggregation levels.

The search space can be classified into a common search space and a UE-specific search space. A certain group of UEs or all UEs can search a common search space of the PDCCH in order to perform dynamic scheduling of system information. In addition, a certain group of terminals or all terminals may search the common search space of the PDCCH in order to receive cell-common control information such as a paging message. For example, the terminal may search the common search space of the PDCCH to receive PDSCH scheduling allocation information for transmission of the SIB including operator information of the cell. In the case of a common search space, since a certain group of UEs or all UEs must receive the PDCCH, it can be defined as a set of pre-defined CCEs. Scheduling assignment information for the UE-specific PDSCH or PUSCH may be received by examining the UE-specific search space of the PDCCH. The UE-specific search space may be defined UE-specifically according to a function of the identity of the UE and various system parameters.

In 5G, a parameter for a search space for a PDCCH may be configured from a base station to a terminal using higher layer signaling (eg, SIB, MIB, RRC signaling). For example, the base station can set the number of PDCCH candidates in each aggregation level L, the monitoring period for the search space, the monitoring occasion in symbol units within the slot for the search space, the search space type (eg, common search space or UE-specific search space), the combination of the DCI format and RNTI to be monitored in the search space, the control resource set index to monitor the search space, and the like. For example, configuration information on a search space for a PDCCH may include information listed in Table 9 below. However, according to an embodiment, the setting information for the search space for the PDCCH is not limited to the information listed in Table 9.

According to configuration information on the search space for the PDCCH, the base station may configure one or a plurality of search space sets for the terminal. According to an embodiment of the present disclosure, the base station may configure search space set 1 and search space set 2 for the terminal. The base station can configure the terminal to monitor DCI format A scrambled with X-RNTI in search space set 1 in the common search space. The base station may set the terminal to monitor DCI format B scrambled with Y-RNTI in search space set 2 in the terminal-specific search space. "X" and "Y" in X-RNTI and Y-RNTI may correspond to one of various RNTIs described in this disclosure.

According to the setting information, one or a plurality of search space sets may exist in a common search space or a terminal-specific search space. For example, search space set #1 and search space set #2 may be set as a common search space. Search space set #3 and search space set #4 may be set as terminal-specific search spaces.

In the common search space, a combination of the following DCI format and RNTI can be monitored. Of course, according to various embodiments of the present disclosure, the combination is not limited to the following examples.

- DCI format 0_0/1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

- DCI format 2_0 with CRC scrambled by SFI-RNTI

- DCI format 2_1 with CRC scrambled by INT-RNTI

- DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

- DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

In the UE-specific search space, a combination of the following DCI format and RNTI may be monitored. Of course, according to various embodiments of the present disclosure, the combination is not limited to the following examples.

- DCI format 0_0/1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

- DCI format 1_0/1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

The RNTIs disclosed in this disclosure may follow the following definitions and uses.

C-RNTI (Cell RNTI): Use of UE-specific PDSCH scheduling

TC-RNTI (Temporary Cell RNTI): Use for UE-specific PDSCH scheduling

CS-RNTI (Configured Scheduling RNTI): Use of semi-statically configured UE-specific PDSCH scheduling

RA-RNTI (Random Access RNTI): PDSCH scheduling in random access phase

P-RNTI (Paging RNTI): PDSCH scheduling purpose through which paging is transmitted

SI-RNTI (System Information RNTI): PDSCH scheduling purpose for transmitting system information

INT-RNTI (Interruption RNTI): used to inform whether pucturing for PDSCH

TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control command for PUSCH

TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Use to indicate power control command for PUCCH

TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control command for SRS

The DCI formats disclosed in this disclosure may follow the definitions described in Table 10 below.

In 5G, the search space of the aggregation level L in the control resource set p and the search space set s can be expressed as Equation 1 below.

- : aggregation level

- : Carrier index

- : Total number of CCEs present in the control resource set p

- : slot index

- : Number of PDCCH candidates at aggregation level L

- = 0, ... , -1: PDCCH candidate group index of aggregation level L

- = 0, ... , -One

- , , , , ,

- : terminal identifier

The value may correspond to 0 in the case of a common search space.

In the case of a UE-specific search space, the value may be a value that changes according to the identity of the UE (C-RNTI or ID set for the UE by the base station) and the time index.

In 5G, as a plurality of search space sets can be set with different parameters (eg, parameters in Table 9), the set of search space sets monitored by the terminal at each point in time may be different. For example, if search space set #1 is set to an X-slot period and search space set #2 is set to a Y-slot period and X and Y are different, the terminal can monitor both search space set #1 and search space set #2 in a specific slot, and can monitor either search space set #1 or search space set #2 in a specific slot.

[PDCCH: span]

The terminal may perform a terminal capability report for each subcarrier interval in the case of having a plurality of PDCCH monitoring positions within a slot. In this case, the concept of Span can be used. Span means consecutive symbols that the UE can monitor the PDCCH in a slot. Each PDCCH monitoring position can be within one span. Span can be expressed as (X, Y), where X means the minimum number of symbols that must be separated between the first symbols of two consecutive spans, and Y can mean the number of consecutive symbols that can monitor the PDCCH within one span. At this time, the UE can monitor the PDCCH in a section within Y symbols from the first symbol of Span within Span.

6 illustrates an example in which a terminal may have a plurality of PDCCH monitoring positions in a slot through Span in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 6 , Span, for example, (X, Y) may be (7,3), (4,3), or (2,2). Each span is indicated by reference numerals 610, 620 and 630 in FIG. According to an embodiment, the span 610 may represent a case where two spans that can be expressed as (7,3) exist in a slot. Therefore, in the span 610 of FIG. 6, the interval X between the first symbols of two spans is 7, and PDCCH monitoring positions may exist within a total of Y (ie, 3) symbols from the first symbol of each span. Search space 1 and search space 2 may exist in consecutive symbols represented by Y=3. According to another embodiment, the span 620 may represent a case in which a total of three spans that can be expressed as (4,3) exist in a slot. In this case, the interval between the second and third spans may be separated by X'=5 symbols larger than the minimum number of symbols X (ie, 4). According to an embodiment, the span 630 may represent a case where a total of 7 spans that can be expressed as (2,2) exist in a slot. In this case, a PDCCH monitoring position may exist within a total of Y=2 symbols from the first symbol of each Span, and search space 3 may exist within Y=2 symbols.

[PDCCH: UE Capability Report]

Slot positions in which the above-described common search space and the UE-specific search space are located may be indicated by the monitoringSlotPeriodicityAndOffset parameter of Table 9, which indicates configuration information on the search space for the PDCCH. In addition, the position of the symbol in the slot may be indicated as a bitmap through the monitoringSymbolsWithinSlot parameter of Table 9. Meanwhile, a symbol position within a slot in which search space monitoring is possible by the terminal may be reported to the base station through the following UE capabilities.

-As described in Table 11 below, UE capability 1 (hereafter referred to as FG (feature group) 3-1) is a type 1 and type 3 common search space or a UE-specific search space. If there is one monitoring occasion (MO) in a slot, it may mean the ability to monitor the corresponding MO when the corresponding MO location is located within the first 3 symbols in the slot. UE capability 1 may be a mandatory capability that all UEs supporting NR must support. Whether UE capability 1 is supported may not be explicitly reported to the base station. However, according to embodiments of the present disclosure, it is not limited to the above-described examples.

-As described in Table 12 below, UE capability 2 (hereinafter referred to as FG 3-2) is a monitoring occasion (MO) for a common search space or a UE-specific search space, when one exists in a slot. It can mean the ability to monitor regardless of the starting symbol position of the corresponding MO. According to various embodiments of the present disclosure, UE capability 2 may be selectively supported by the UE. Whether UE capability 2 is supported may be explicitly reported to the base station. However, according to embodiments of the present disclosure, it is not limited to the above-described examples.

- UE capability 3 (hereinafter mixed with FG 3-5, 3-5a, 3-5b), as described in Table 13a or Table 13b below, monitoring locations for a common search space or a UE-specific search space (monitoring occasions, if there are a plurality of MOs in a slot, the UE may indicate a pattern of MOs that can be monitored. The above pattern may consist of a start symbol interval X between different MOs and a maximum symbol length Y for one MO. The combination of (X,Y) supported by the terminal may be one or a plurality of {(2,2), (4,3), (7,3)}. According to various embodiments of the present disclosure, UE capability 3 may be selectively supported by the UE. Whether or not the capability is supported and the above-described (X,Y) combination may be explicitly reported to the base station.

The UE may report whether or not to support UE capability 2 and/or UE capability 3 and related parameters to the BS. The base station may perform time axis resource allocation for a common search space and a terminal-specific search space based on the reported terminal capabilities. When allocating resources, the base station may not place the MO in a position where the terminal cannot monitor.

[PDCCH: BD/CCE limit]

When a plurality of search space sets are configured for a terminal, the following conditions may be considered in a method for determining a search space set to be monitored by a terminal.

According to an embodiment, when the value of monitoringCapabilityConfig-r16, which is higher layer signaling, is set to r15monitoringcapability, the terminal may define the maximum value for the number of PDCCH candidates that can be monitored and the maximum number of CCEs constituting the entire search space (for example, the entire search space may mean the entire CCE set corresponding to a union region of a plurality of search space sets) for each slot. According to an embodiment, when the value of monitoringCapabilityConfig-r16 is set to r16monitoringcapability, the terminal may define the maximum value for the number of PDCCH candidate groups that can be monitored and the number of CCEs constituting the entire search space (for example, the entire search space corresponds to the entire CCE set corresponding to a union region of a plurality of search space sets) for each span. monitoringCapabilityConfig-r16 may refer to setting information in Tables 14a and 14b below. However, according to various embodiments of the present disclosure, the above-described setting information is not limited to the following.

[Condition 1: Limit the maximum number of PDCCH candidates]

According to an embodiment, M ^μ , the maximum number of PDCCH candidates that can be monitored by a UE, may be set to a subcarrier interval of 15 2 ^μ kHz in a cell according to a configuration value of higher layer signaling. According to an embodiment, when M ^μ is defined on a slot basis, Table 15a below may be followed, and when M μ is defined on a span basis, Table 15b below may be followed.

[Condition 2: Limit the maximum number of CCEs]

According to an embodiment, the cell may refer to the entire search space (for example, the entire search space may mean a set of all CCEs corresponding to a union region of a plurality of search space sets) according to a setting value of higher layer signaling. C ^μ , which is the maximum number of CCEs constituting the search space, may be set to a subcarrier interval of 15 2 ^μ kHz. According to an embodiment, when C ^μ is defined on a slot basis, Table 16a below may be followed, and when C μ is defined on a span basis, Table 16b below may be followed.

For convenience of description, a situation in which both conditions 1 and 2 are satisfied at a specific point in time is defined as “condition A”. Accordingly, not satisfying condition A may mean not satisfying at least one of conditions 1 and 2.

[PDCCH: Overbooking]

Depending on the setting of search space sets of the base station, a case in which condition A is not satisfied may occur at a specific point in time. When condition A is not satisfied at a specific time point, the terminal may select and monitor only a part of search space sets configured to satisfy condition A at that time point. When condition A is not satisfied at a specific time point, the base station may transmit the PDCCH through the selected search space set.

As a method of selecting some search spaces from the set of all set search spaces, the following method may be followed.

When condition A for the PDCCH is not satisfied at a specific time point (or a specific slot), the UE (or the base station) may preferentially select a search space set in which the search space type is set as a common search space from among search space sets existing at that time, rather than a search space set set as a UE-specific search space.

When all search space sets set as the common search space are selected (that is, when condition A is satisfied even after all search spaces set as the common search space are selected), the terminal (or the base station) may select search space sets set as the terminal-specific search space. In this case, when there are a plurality of search space sets set as the terminal-specific search space, a search space set having a lower search space set index may have a higher priority. The UE may select UE-specific search space sets within a range where condition A is satisfied in consideration of priority.

[QCL, TCI state]

In a wireless communication system, one or more different antenna ports (or one or more channels, signals, and combinations thereof may be replaced, but in the future description of the present disclosure, for convenience, different antenna ports will be collectively referred to) can be associated with each other by a quasi co-location (QCL) setting as described in Table 17 below. The TCI state may mean to indicate a QCL relationship between a PDCCH (or PDCCH DMRS) and another RS or channel. Saying that a certain reference antenna port A (reference RS #A) and another target antenna port B (target RS #B) are QCLed (QCLed) with each other means that all or some of the large-scale channel parameters estimated by the terminal at antenna port A are allowed to be applied to channel measurement from antenna port B. QCL is 1) time tracking that is affected by average delay and delay spread, 2) frequency tracking that is affected by doppler shift and doppler spread, 3) radio resource management (RRM) that is affected by average gain, 4) It may be necessary to associate different parameters depending on situations such as beam management (BM) that is affected by spatial parameters. Accordingly, in NR, four types of QCL relationships as shown in Table 17 below can be supported.

The spatial RX parameter may mean all or some of various parameters such as angle of arrival (AoA), power angular spectrum (PAS) of AoA, angle of departure (AoD), PAS of AoD, transmit/receive channel correlation, transmit/receive beamforming, or spatial channel correlation.

As described in Table 18 below, the QCL relationship may be set to the UE through the RRC parameters TCI-State and QCL-Info. Referring to Table 18, the base station sets one or more TCI states to the UE and informs the UE of up to two QCL relationships (qcl-Type1, qcl-Type2) for a reference signal (RS) (i.e., target RS) that refers to the ID of the TCI state. At this time, each QCL information (QCL-Info) included in each TCI state may include the serving cell index, BWP index, type of reference RS, ID, or QCL type disclosed in Table 17 of the reference RS indicated by the corresponding QCL information. Of course, according to various embodiments of the present disclosure, information included in the QCL information is not limited to the above example.

7 illustrates an example in which a base station allocates a beam according to TCI state setting in a wireless communication system according to an embodiment of the present disclosure. Referring to FIG. 7 , the base station may transmit information on different N beams to the terminal through different N TCI states. For example, as shown in FIG. 7, when N = 3, the base station has qcl-Type2 parameters included in three TCI states (700, 705, and 710) corresponding to CSI-RS or SSB corresponding to different beams. Can be set to QCL type D so that it can be associated with. Through this, the base station can indicate that antenna ports referring to different TCI states (700, 705, or 710) are associated with different spatial Rx parameters (ie, different beams).

Tables 19a to 19e below show valid TCI state settings according to the type of target antenna port.

Table 19a shows valid TCI state settings when the target antenna port is CSI-RS for tracking (TRS). TRS may mean a non-zero-power (NZP) CSI-RS in which the repetition parameter is not set among CSI-RSs and trs-Info is set to true in the configuration information illustrated in Tables 20a and 20b below. In the case of setting No. 3 in Table 19a, it can be used for aperiodic TRS. However, according to various embodiments of the present disclosure, TCI state settings may not be limited to the example described in Table 19a.

Table 19b shows valid TCI state settings when the target antenna port is CSI-RS for CSI. CSI-RS for CSI may refer to an NZP CSI-RS in which a parameter indicating repetition (eg, a repetition parameter) is not set and trs-Info is not set to true among CSI-RSs. However, according to various embodiments of the present disclosure, TCI state settings may not be limited to the example described in Table 19b.

Table 19c shows valid TCI state settings when the target antenna port is CSI-RS for beam management (eg, CSI-RS for L1 reference signal received power (RSRP) reporting). CSI-RS for BM may mean an NZP CSI-RS in which a repetition parameter is set among CSI-RSs and may have a value of On or Off, and trs-Info is not set to true. However, according to various embodiments of the present disclosure, TCI state settings may not be limited to the example described in Table 19c.

Table 19d below shows valid TCI state settings when the target antenna port is PDCCH DMRS. However, according to various embodiments of the present disclosure, TCI state settings may not be limited to the example described in Table 19d.

Table 19e below shows valid TCI state settings when the target antenna port is PDSCH DMRS. However, according to various embodiments of the present disclosure, TCI state settings may not be limited to the example described in Table 19e.

According to an embodiment of the present disclosure, in the QCL setting method according to Tables 19a to 19e described above, the target antenna port and reference antenna port for each step may be set and operated as "SSB" ⇒ "TRS" ⇒ "CSI-RS for CSI, CSI-RS for BM, PDCCH DMRS, or PDSCH DMRS". Through this, it may be possible to help the reception operation of the terminal by linking statistical characteristics measurable from the SSB and TRS to each antenna port.

For configuration information of trs-Info related to NZP CSI-RS, refer to Tables 20a and 20b below. However, according to various embodiments of the present disclosure, configuration information of trs-Info may not be limited to the example described in Table 20a or Table 20b.

[PDCCH: related to TCI state]

Specifically, the TCI state combinations applicable to the PDCCH DMRS antenna port are as disclosed in Table 21 below. In Table 21, the fourth row may be a combination assumed by the UE before RRC configuration, and it may be impossible to configure after RRC configuration.

8 illustrates an example of a TCI state allocation method for a PDCCH in a wireless communication system according to an embodiment of the present disclosure. Specifically, in NR, a hierarchical signaling method as shown in FIG. 8 may be supported for dynamic allocation of PDCCH beams.

Referring to FIG. 8, the base station can set N TCI states (805, 810, ..., 820) to the terminal through RRC signaling 800, and some of them can be set as TCI states for CORESET (825). Thereafter, the base station may instruct the terminal of one of the TCI states (830, 835, 840) for CORESET through MAC CE (MAC Control Element) signaling (845). Thereafter, the UE may receive the PDCCH based on beam information included in the TCI state indicated by MAC CE signaling.

9 illustrates a TCI indication MAC CE signaling structure for PDCCH DMRS in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 9, TCI indication MAC CE signaling for PDCCH DMRS may consist of 2 bytes (16 bits) (Oct1 (900), Oct2 (905)), and may include 5-bit serving cell ID 915, 4-bit CORESET ID 920, and 7-bit TCI state ID 925.

10 illustrates beam configuration of a control resource set and a search space in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 10, the base station may instruct the terminal one of the TCI state lists 1005 included in the CORESET 1000 configuration through MAC CE signaling. Thereafter, until another TCI state is indicated to the corresponding CORESET through another MAC CE signaling, the terminal may consider or determine that the same QCL information (beam #1 (1005)) is applied to one or more search spaces #1, #2, and #3 (1010, 1015, and 1020) connected to the CORESET. In the aforementioned PDCCH beam allocation method, it may be difficult to indicate a beam change faster than the MAC CE signaling delay. In addition, the aforementioned PDCCH beam allocation method makes it difficult to operate a flexible PDCCH beam because the same beam is collectively applied to each CORESET regardless of search space characteristics.

Hereinafter, embodiments of the present disclosure are intended to provide a more flexible PDCCH beam configuration and operation method. In describing the embodiments of the present disclosure below, several distinct examples are provided for convenience of explanation, but the illustrated embodiments are not mutually exclusive, and two or more embodiments may be appropriately combined and applied according to circumstances.

The base station may set one or a plurality of TCI states for a specific control resource set to the terminal. The base station may activate one of the configured TCI states through a MAC CE activation command. For example, control resource set #1 may have {TCI state#0, TCI state#1, TCI state#2} set as TCI states. The base station may transmit a command activating the terminal to assume TCI state #0 as the TCI state for the control resource set #1 through the MAC CE. The UE may receive the DMRS of the corresponding control resource set based on the activation command for the TCI state received through the MAC CE. The UE may receive the DMRS of the corresponding control resource set based on QCL information in the activated TCI state.

For the control resource set (control resource set #0) whose index is set to 0, if the UE does not receive the MAC CE activation command for the TCI state of the control resource set #0, the UE can assume QCL with the SS/PBCH block (SSB) identified in the initial access procedure or non-contention or contention free random access procedure that is not triggered by the PDCCH command for the DMRS transmitted in the control resource set #0.

For a control resource set (control resource set #X) whose index is set to a value other than 0 (X), if the terminal does not receive the TCI state for the control resource set #X, or sets one or more TCI states but does not receive a MAC CE activation command to activate one of them, the terminal can assume that the DMRS transmitted from the control resource set #X is QCL with the SS/PBCH block identified in the initial access process.

[PDCCH: related to QCL prioritization rule]

In the following, the QCL priority determination operation for the PDCCH is described in detail.

The terminal may operate with carrier aggregation (CA) within a single cell or band. When a plurality of control resource sets existing within an activated bandwidth portion of a single cell or a plurality of cells overlap each other in time while having the same or different QCL-TypeD characteristics in a specific PDCCH monitoring interval, the UE selects a specific control resource set according to a QCL priority determination operation and monitors control resource sets having the same QCL-TypeD characteristics as the corresponding control resource set. That is, when a plurality of control resource sets overlap in time, the terminal can receive only one QCL-TypeD characteristic. In this case, the criteria for determining the QCL priority may be as follows.

- Criterion 1: A set of control resources connected to the common search interval of the lowest index within a cell corresponding to the lowest index among cells including a common search interval.

- Criterion 2: A control resource set associated with a UE-specific search interval having the lowest index within a cell corresponding to the lowest index among cells including a UE-specific search interval.

As described above, for each criterion, if the criterion is not satisfied, the next criterion may be additionally applied. For example, when control resource sets overlap in time in a specific PDCCH monitoring period, if all control resource sets are not connected to a common search period but are connected to a terminal-specific search period (i.e., when criterion 1 is not satisfied), the terminal may omit the application of criterion 1 and apply criterion 2. However, according to various embodiments of the present disclosure, criteria applied by the terminal may not be limited to the above-described examples.

When selecting a control resource set based on the above criteria, the terminal may additionally consider the following two items for QCL information set in the control resource set. First, when control resource set 1 has CSI-RS 1 as a reference signal having a QCL-TypeD relationship, SSB 1 is a reference signal having a QCL-TypeD relationship, and another control resource set 2 has a QCL-TypeD relationship. Second, control resource set 1 has CSI-RS 1 set in cell 1 as a reference signal having a QCL-TypeD relationship, CSI-RS 1 has a QCL-TypeD relationship, SSB 1, control resource set 2 has a CSI-RS 2 set in cell 2 as a reference signal having a QCL-TypeD relationship, and CSI-RS 2 has a QCL-TypeD relationship, and the reference signal having a QCL-TypeD relationship is the same SSB In case of 1, the terminal may determine or consider that the two control resource sets have the same QCL-TypeD characteristics.

11 illustrates an example of a method for selecting a receivable control resource set in consideration of priority when a terminal receives a downlink control channel in a wireless communication system according to an embodiment of the present disclosure.

According to an embodiment, referring to FIG. 11 , a terminal may be configured to receive a plurality of control resource sets overlapping in time in a specific PDCCH monitoring period 1110 . A plurality of control resource sets set to be received by the terminal may be connected to a common search space or a terminal specific search space for a plurality of cells. According to an embodiment, within the PDCCH monitoring period, within the first bandwidth part 1100 of the first cell, the first control resource set (CORESET #1) 1115 connected to the first common search period (CSS#1) may exist. According to an embodiment, within the first bandwidth portion 1105 of the second cell within the corresponding PDCCH monitoring interval, the first control resource set (CORESET#1) 1120 connected to the first common search period (CSS#1) and the second control resource set (CORESET#2) 1125 connected to the second terminal-specific search period (USS#2) may exist. The control resource set 1115 and the control resource set 1120 may have a relationship of QCL-TypeD and CSI-RS resource #1 configured within the #1 bandwidth part of cell #1. The control resource set 1125 may have a QCL-TypeD relationship with CSI-RS resource No. 1 set within the bandwidth part No. 1 of cell No. 2. Therefore, when criterion 1 is applied to the corresponding PDCCH monitoring period 1110, the terminal can receive all other control resource sets having the same QCL-TypeD reference signal as the first control resource set 1115. Therefore, the terminal can receive the control resource set 1115 and the control resource set 1120 in the corresponding PDCCH monitoring period 1110.

According to various embodiments of the present disclosure, referring to FIG. 11 , a terminal may receive reception of a plurality of control resource sets overlapping in time in a specific PDCCH monitoring period 1140 . A plurality of control resource sets set to be received by the terminal may be connected to a common search space or a terminal specific search space for a plurality of cells. Within the corresponding PDCCH monitoring interval, within the first bandwidth portion 1130 of cell #1, there may be a first control resource set (CORESE#1) 1145 connected to the first terminal-specific search period (USS#1) and a second control resource set (CORESET#2) 1150 connected to the second terminal-specific search period (USS#2). Within the corresponding PDCCH monitoring interval, within the first bandwidth portion 1135 of the second cell, the first control resource set (CORESET#1) 1155 connected to the first terminal-specific search period (USS#1) and the second control resource set (CORESET#2) 1160 connected to the third terminal-specific search period (USS#3) may exist. The control resource set 1145 and the control resource set 1150 may have a relationship of QCL-TypeD and CSI-RS resource number 1 configured within the number 1 bandwidth part of cell number 1. The control resource set 1155 may have a QCL-TypeD relationship with CSI-RS resource No. 1 set within the bandwidth part No. 1 of cell No. 2. The control resource set 1160 may have a QCL-TypeD relationship with the second CSI-RS resource set within the first bandwidth portion of the second cell. When criterion 1 is applied to the PDCCH monitoring period 1140, since there is no common search period, the terminal can apply criterion 2, which is the next criterion. If criterion 2 is applied to the PDCCH monitoring period 1140, the terminal can receive all other control resource sets having QCL-TypeD reference signals such as the control resource set 1145. Therefore, the terminal can receive the control resource set 1145 and the control resource set 1150 in the corresponding PDCCH monitoring period 1140 .

12 illustrates an example of frequency axis resource allocation of a PDSCH in a wireless communication system according to an embodiment of the present disclosure. Referring to FIG. 12, resource assignment (RA) type 0 (1200), RA type 1 (1205), and dynamic switch (RA type 0, RA type 1) 1210, which can be set through higher layer signaling, are shown.

Referring to FIG. 12, if a UE is configured to use only RA type 0 (1200) through higher layer signaling, some downlink control information (DCI) for allocating a PDSCH to the corresponding UE may include a bitmap 1215 composed of N _RBG bits. In this case, N _RBG may mean the number of resource block groups (RBGs) determined as shown in Table 22 below according to the BWP size allocated by the BWP indicator and the higher layer parameter rbg-Size. According to an embodiment, data may be transmitted in an RBG indicated by 1 by a bitmap.

When a UE is configured to use only RA type 1 1205 through higher layer signaling, some DCIs allocating a PDSCH to the corresponding UE are It may include frequency axis resource allocation information consisting of N bits. The stated N ^DL,BWP _RB is the number of RBs in the downlink bandwidth part (BWP). The base station may set the starting VRB 1220 and the length 1225 of frequency axis resources continuously allocated therefrom through frequency axis resource allocation information.

When the terminal is configured to use both RA type 0 and RA type 1 through higher layer signaling (1210), some DCIs for allocating a PDSCH to the terminal may include frequency axis resource allocation information composed of bits of a larger value (1235) among the payload for setting RA type 0 and the payload for setting RA type 1. At this time, one bit 1230 is added to the first part (eg, most significant bit, MSB) of the frequency axis resource allocation information in DCI to indicate the use of RA type 0 or RA type 1. For example, when the corresponding bit 1230 has a value of '0', it may indicate that RA type 0 is used, and when it has a value of '1', it may indicate that RA type 1 is used.

[PDSCH/PUSCH: related to time resource allocation]

Hereinafter, a time domain resource allocation method for a data channel in a next-generation wireless communication system (5G or NR system) will be described.

The base station may set a table for time domain resource allocation information for the downlink data channel (PDSCH) and the uplink data channel (PUSCH) to the terminal through higher layer signaling (eg, RRC signaling). For the PDSCH, a table consisting of maxNrofDL-Allocations = 16 entries can be set. For PUSCH, a table consisting of maxNrofUL-Allocations = 16 entries can be set. According to an embodiment, the time domain resource allocation information includes PDCCH-to-PDSCH slot timing (e.g., a time interval in units of slots between when a PDCCH is received and when a PDSCH scheduled by the received PDCCH is transmitted, hereinafter referred to as K0), PDCCH-to-PUSCH slot timing (e.g., a time interval in units of slots between when a PDCCH is received and a time when a PUSCH scheduled by the received PDCCH is transmitted, hereinafter referred to as K2), At least one of information about the location and length of a start symbol in which the PDSCH or PUSCH is scheduled within the slot and a mapping type of the PDSCH or PUSCH may be included. For example, information as described in Table 23 or Table 24 below may be transmitted from the base station to the terminal. However, according to an embodiment of the present disclosure, information included in time domain resource allocation information may not be limited to the above-described example.

The base station may notify the terminal of one of the entries of the above-described time-domain resource allocation information table through L1 signaling (eg, DCI). According to an embodiment, one of the table entries for time domain resource allocation information may be indicated as a 'time domain resource allocation' field in DCI. The terminal may obtain time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

13 illustrates an example of time domain resource allocation of a PDSCH in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 13, a base station uses PDSCH resources according to an OFDM symbol start position (S) 1300 and a length 1305 in one slot 1310 dynamically indicated through subcarrier spacing (SCS) ( μ _PDSCH , μ _PDCCH ) of a data channel and a control channel configured using higher layer signaling, a scheduling offset (K0) value, or DCI. At least one of the time axis positions of may be indicated.

14 illustrates an example of time domain resource allocation according to subcarrier intervals of a data channel and a control channel in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 14, when the subcarrier spacing (SCS) ( μ _PDSCH and μ _PDCCH ) of the data channel and the control channel are the same (ie, μ _PDSCH = μ _PDCCH ) (1400), since the slot numbers for data and control are the same, the base station and the terminal can generate a scheduling offset according to a predetermined slot offset K0. On the other hand, when the subcarrier intervals of the data channel and the control channel are different (i.e., μ _PDSCH ≠ μ _PDCCH ) (1405), since the slot numbers for data and control are different, the base station and the terminal can generate a scheduling offset according to a predetermined slot offset K0 based on the subcarrier interval of the PDCCH. According to an embodiment, when the terminal receives a DCI indicating a bandwidth part change in slot n, and the slot offset value indicated by the corresponding DCI is K0, the terminal can receive data through a PDSCH scheduled in slot n + K0.

[SRS related]

Hereinafter, a method for estimating an uplink channel using SRS (sounding reference signal) transmission of a terminal will be described. The base station may set at least one SRS configuration for each uplink BWP to deliver configuration information for SRS transmission to the terminal. In addition, at least one SRS resource set may be set for each SRS configuration. According to an embodiment, the base station and the terminal may send and receive higher signaling information as follows to deliver information about the SRS resource set.

- srs-ResourceSetId: SRS resource set index

- srs-ResourceIdList: A set of SRS resource indexes referenced by the SRS resource set

- resourceType: Time axis transmission setting of the SRS resource referenced by the SRS resource set, which can be set to one of 'periodic', 'semi-persistent', and 'aperiodic'. If set to 'periodic' or 'semi-persistent', associated CSI-RS information may be provided according to the usage of the SRS resource set. If set to 'aperiodic', at least one of an aperiodic SRS resource trigger list or slot offset information may be provided, and associated CSI-RS information may be provided according to the usage of the SRS resource set.

- usage: As a setting for the usage of the SRS resource referenced in the SRS resource set, one of 'beamManagement', 'codebook', 'nonCodebook', and 'antennaSwitching' can be set.

- alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: Parameter settings for adjusting the transmission power of the SRS resource referenced by the SRS resource set may be provided.

The UE can understand that the SRS resource included in the set of SRS resource indexes referenced by the SRS resource set follows the information set in the SRS resource set.

The base station and the terminal may transmit and receive higher layer signaling information to deliver individual configuration information for the SRS resource. According to an embodiment, the individual configuration information for the SRS resource may include time-frequency axis mapping information within a slot of the SRS resource. Time-frequency axis mapping information within a slot of the SRS resource may include information on frequency hopping within a slot or between slots of the SRS resource. According to an embodiment, the individual configuration information for the SRS resource may include time axis transmission configuration of the SRS resource. Time axis transmission of the SRS resource can be set to one of 'periodic', 'semi-persistent', and 'aperiodic'. Time axis transmission of the SRS resource may be limited to have the same time axis transmission setting as the SRS resource set including the SRS resource. When the time axis transmission setting of the SRS resource is set to 'periodic' or 'semi-persistent', the SRS resource transmission period and slot offset (eg, periodicityAndOffset) may be additionally included in the time axis transmission setting.

The base station may activate, deactivate, or trigger SRS transmission to the terminal through higher layer signaling including RRC signaling or MAC CE signaling, or L1 signaling (eg, DCI). For example, the base station may activate or deactivate periodic SRS transmission through higher layer signaling to the terminal. The base station may instruct to activate an SRS resource set in which resourceType is set to periodic through higher layer signaling. The UE may transmit an SRS resource referred to in an activated SRS resource set. Time-frequency axis resource mapping within the slot of the transmitted SRS resource may follow resource mapping information set in the SRS resource, and slot mapping including transmission period and slot offset may follow periodicityAndOffset set in the SRS resource. In addition, the spatial domain transmission filter applied to the transmitted SRS resource may refer to spatial relation info set in the SRS resource or associated CSI-RS information set in the SRS resource set including the SRS resource. The UE may transmit the SRS resource within the uplink BWP activated for the periodic SRS resource activated through higher layer signaling.

The base station may activate or deactivate semi-persistent SRS transmission through higher layer signaling to the terminal. The base station may instruct to activate the SRS resource set through MAC CE signaling. The UE may transmit an SRS resource referred to in an activated SRS resource set. An SRS resource set activated through MAC CE signaling may be limited to an SRS resource set whose resourceType is set to semi-persistent. Time-frequency axis resource mapping within the slot of the transmitted SRS resource may follow resource mapping information set in the SRS resource, and slot mapping including transmission period and slot offset may follow periodicityAndOffset set in the SRS resource. The spatial domain transmission filter applied to the transmitted SRS resource may refer to spatial relation info set in the SRS resource or associated CSI-RS information set in the SRS resource set including the SRS resource. When spatial relation info is set in the SRS resource, a spatial domain transmission filter may be determined by referring to configuration information on spatial relation info delivered through MAC CE signaling that activates semi-persistent SRS transmission instead of following it. The UE may transmit the SRS resource within the uplink BWP activated for the semi-persistent SRS resource activated through higher layer signaling.

The base station may trigger aperiodic SRS transmission to the terminal through DCI. The base station may indicate one of the aperiodic SRS resource triggers (aperiodicSRS-ResourceTrigger) through the SRS request field of the DCI. The terminal may determine or understand that an SRS resource set including an aperiodic SRS resource trigger indicated through DCI in an aperiodic SRS resource trigger list among configuration information of the SRS resource set is triggered. The UE may transmit the SRS resource referred to in the triggered SRS resource set. Time-frequency axis resource mapping within a slot of a transmitted SRS resource may follow resource mapping information set in the SRS resource. Slot mapping of the transmitted SRS resource may be determined through a slot offset between the PDCCH including DCI and the SRS resource, and may refer to a value (s) included in a slot offset set set in the SRS resource set. Specifically, a value indicated by a time domain resource assignment field of DCI among offset value(s) included in a slot offset set set in an SRS resource set may be applied to a slot offset between a PDCCH including DCI and an SRS resource. The spatial domain transmission filter applied to the transmitted SRS resource may refer to spatial relation info set in the SRS resource or associated CSI-RS information set in the SRS resource set including the SRS resource. The UE may transmit an SRS resource within an activated uplink BWP for an aperiodic SRS resource triggered through DCI.

When the base station triggers aperiodic SRS transmission to the terminal through DCI, in order for the terminal to transmit the SRS by applying the configuration information for the SRS resource, the PDCCH including the DCI that triggers the aperiodic SRS transmission and the transmitting SRS. A minimum time interval may be required. The time interval for SRS transmission of the UE is the number of symbols between the last symbol of the PDCCH including the DCI triggering aperiodic SRS transmission and the first symbol to which the SRS resource transmitted first among the transmitted SRS resource(s) is mapped. It can be defined as the number of symbols. The minimum time interval may be determined by referring to the PUSCH preparation procedure time required for the UE to prepare for PUSCH transmission. In addition, the minimum time interval may have a different value depending on where an SRS resource set including a transmitted SRS resource is used. For example, the minimum time interval may be defined as an N2 symbol defined by referring to the PUSCH preparation procedure time of the UE and considering UE processing capability according to capability or capability of the UE. In addition, considering the usage of the SRS resource set including the transmitted SRS resource, when the usage of the SRS resource set is set to 'codebook' or 'antennaSwitching', the minimum time interval may be determined as N2 symbols. When the usage of the SRS resource set is set to 'nonCodebook' or 'beamManagement', the minimum time interval may be determined by N2+14 symbols. The UE may transmit the aperiodic SRS when the time interval for aperiodic SRS transmission is greater than or equal to the minimum time interval. If the time interval for aperiodic SRS transmission is smaller than the minimum time interval, the UE may ignore the DCI triggering the aperiodic SRS.

The above-described spatialRelationInfo setting information of Table 25 refers to one reference signal and can be applied to a beam used for SRS transmission of beam information of the corresponding reference signal. For example, the setting of spatialRelationInfo may include information such as Table 26 below. However, according to embodiments of the present disclosure, it may not be limited to the examples disclosed in Tables 25 and 26.

Referring to the spatialRelationInfo setting, the index of a reference signal that the UE wishes to refer to in order to use beam information of a specific reference signal from the base station may be set to an SS/PBCH block index, a CSI-RS index, or an SRS index. The higher layer referenceSignal may be setting information indicating which beam information of a reference signal is referred to for corresponding SRS transmission. ssb-Index may mean the index of the SS/PBCH block, csi-RS-Index may mean the index of CSI-RS, and srs may mean the index of SRS. When the value of higher layer signaling referenceSignal is set to 'ssb-Index', the UE can apply the RX beam used when receiving the SS/PBCH block corresponding to the ssb-Index as the transmit beam of the corresponding SRS transmission. When the value of higher layer signaling referenceSignal is set to 'csi-RS-Index', the UE can apply the Rx beam used when receiving the CSI-RS corresponding to the csi-RS-Index as the Tx beam of the corresponding SRS transmission. When the value of higher layer signaling referenceSignal is set to 'srs', the terminal can apply the transmission beam used when transmitting the SRS corresponding to srs as the transmission beam of the corresponding SRS transmission.

[PUSCH: related to transmission method]

Hereinafter, a description of a PUSCH transmission scheduling method will be described in detail. PUSCH transmission can be dynamically scheduled by a UL grant in DCI or operated by configured grant Type 1 or Type 2. Dynamic scheduling indication for PUSCH transmission may be provided through DCI format 0_0 or 0_1.

Configured grant Type 1 PUSCH transmission may be semi-statically set through reception of configuredGrantConfig including rrc-ConfiguredUplinkGrant of Table 27 through higher layer signaling without receiving the UL grant in DCI. Configured grant Type 2 PUSCH transmission can be scheduled semi-persistently by UL grant in DCI after receiving configuredGrantConfig not including rrc-ConfiguredUplinkGrant in Table 27 through higher signaling. When PUSCH transmission operates by configured grant, parameters applied to PUSCH transmission are dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, scaling of UCI-OnPUSCH provided in pushch-Config of Table 28, which is higher layer signaling. Except for, it can be applied through higher layer signaling, configuredGrantConfig of Table 27. When the UE is provided with transformPrecoder in configuredGrantConfig, which is higher layer signaling of Table 27, the UE can apply tp-pi2BPSK in push-Config of Table 28 to PUSCH transmission operated by the configured grant. However, according to various embodiments of the present disclosure, applied parameters may not be limited to the above-described examples.

Hereinafter, a description of the PUSCH transmission method will be described. A DMRS antenna port for PUSCH transmission may be the same as an antenna port for SRS transmission. PUSCH transmission may follow a codebook-based transmission method and a non-codebook-based transmission method, respectively, depending on whether the value of txConfig in push-Config of Table 28, which is higher layer signaling, is 'codebook' or 'nonCodebook'.

As described above, PUSCH transmission can be dynamically scheduled through DCI format 0_0 or 0_1, and can be semi-statically set by configured grant. When the UE is instructed to schedule PUSCH transmission through DCI format 0_0, the UE can perform beam configuration for PUSCH transmission using the pucch-spatialRelationInfoID corresponding to the UE-specific PUCCH resource corresponding to the minimum ID within the uplink BWP activated in the serving cell. In this case, PUSCH transmission can be performed based on a single antenna port. The UE may not expect scheduling for PUSCH transmission through DCI format 0_0 in a BWP in which PUCCH resource including pucch-spatialRelationInfo is not configured. If the UE is not configured with txConfig in push-Config of Table 28 below, the UE may not expect to be scheduled in DCI format 0_1.

Hereinafter, a description of codebook-based PUSCH transmission is described. Codebook-based PUSCH transmission can be dynamically scheduled through DCI format 0_0 or 0_1, and can operate quasi-statically by configured grant. When the codebook-based PUSCH is dynamically scheduled by DCI format 0_1 or quasi-statically configured by a configured grant, the terminal can determine a precoder for PUSCH transmission based on the SRS Resource Indicator (SRI), Transmission Precoding Matrix Indicator (TPMI), and transmission rank (i.e., the number of PUSCH transmission layers).

SRI may be given through a field SRS resource indicator in DCI or set through srs-ResourceIndicator, which is higher layer signaling. The terminal can receive at least one SRS resource when transmitting codebook-based PUSCH, and can receive up to two. When a UE receives SRI through DCI, the SRS resource indicated by the SRI may mean an SRS resource corresponding to the SRI among SRS resources transmitted prior to the PDCCH including the SRI. TPMI and transmission rank can be given through fields precoding information and number of layers in DCI. TPMI and transmission rank can be set through precodingAndNumberOfLayers, which is higher layer signaling. TPMI may be used to indicate a precoder applied to PUSCH transmission. When a UE is configured with one SRS resource, TPMI may be used to indicate a precoder to be applied in one configured SRS resource. When the UE is configured with a plurality of SRS resources, TPMI may be used to indicate a precoder to be applied in the SRS resource indicated through the SRI.

A precoder to be used for PUSCH transmission may be selected from an uplink codebook having the same number of antenna ports as the value of nrofSRS-Ports in SRS-Config, which is higher layer signaling. In codebook-based PUSCH transmission, a UE may determine a codebook subset based on TPMI and codebookSubset in push-Config, which is higher layer signaling. CodebookSubset in push-Config, which is higher layer signaling, may be set to one of 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the UE capability reported by the terminal to the base station. When the UE reports 'partialAndNonCoherent' as the UE capability, the UE may not expect the value of codebookSubset, which is higher layer signaling, to be set to 'fullyAndPartialAndNonCoherent'. If the terminal reports 'nonCoherent' as the UE capability, the terminal may not expect the value of codebookSubset, which is higher signaling, to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. If nrofSRS-Ports in SRS-ResourceSet, which is higher layer signaling, indicates two SRS antenna ports, the UE may not expect that the value of codebookSubset, which is higher layer signaling, is set to 'partialAndNonCoherent'.

The terminal may receive one SRS resource set in which the value of usage in the SRS-ResourceSet, which is higher layer signaling, is set to 'codebook'. One SRS resource within the configured SRS resource set may be indicated through SRI. When several SRS resources are set in an SRS resource set in which the usage value in the SRS-ResourceSet, which is higher signaling, is set to 'codebook', the terminal has the value of nrofSRS-Ports in the SRS-Resource, which is higher-layer signaling, for all SRS resources. It can be expected that the same value is set.

The terminal may transmit one or a plurality of SRS resources included in the SRS resource set in which the value of usage is set to 'codebook' to the base station according to higher layer signaling. The base station may select one of the SRS resources transmitted by the terminal and instruct the terminal to perform PUSCH transmission using transmission beam information of the selected SRS resource. In this case, in codebook-based PUSCH transmission, SRI can be used as information for selecting an index of one SRS resource and can be included in DCI. Additionally, the base station may include information indicating the TPMI and rank to be used by the terminal for PUSCH transmission in the DCI. The UE may use the SRS resource indicated by the SRI. Rank and TPMI may be indicated based on the transmission beam of the SRS resource indicated by the SRI. The UE may perform PUSCH transmission by applying the rank indicated by the SRI and the precoder indicated by the TPMI based on the transmission beam of the SRS resource indicated by the SRI.

Hereinafter, a description of PUSCH transmission based on non-codebook will be described. Non-codebook based PUSCH transmission can be dynamically scheduled through DCI format 0_0 or 0_1, and can operate quasi-statically by configured grant. When at least one SRS resource is set in the SRS resource set in which the value of usage in the SRS-ResourceSet, which is higher signaling, is set to 'nonCodebook', the terminal can receive non-codebook based PUSCH transmission scheduling through DCI format 0_1.

For an SRS resource set in which the value of usage in the SRS-ResourceSet, which is higher layer signaling, is set to 'nonCodebook', the terminal can receive one connected NZP CSI-RS (non-zero power CSI-RS) resource set. The UE may calculate a precoder for SRS transmission through measurement of NZP CSI-RS resource connected to the SRS resource set. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource associated with the SRS resource set and the first symbol of aperiodic SRS transmission in the terminal is less than 42 symbols, the terminal is a precoder for SRS transmission. You may not expect information to be updated.

When the value of resourceType in SRS-ResourceSet, which is higher layer signaling, is set to 'aperiodic', the connected NZP CSI-RS may be indicated by SRS request, which is a field in DCI format 0_1 or 1_1. When the connected NZP CSI-RS resource is an aperiodic NZP CSI-RS resource, the existence of the connected NZP CSI-RS for the case where the value of the field SRS request in DCI format 0_1 or 1_1 is not '00'. It can be indicated. In this case, the corresponding DCI may not indicate cross carrier or cross BWP scheduling. In addition, if the value of the SRS request indicates the existence of the NZP CSI-RS, the corresponding NZP CSI-RS may be located in a slot in which the PDCCH including the SRS request field is transmitted. In this case, the TCI states set for the scheduled subcarriers may not be set to QCL-TypeD.

When a periodic or semi-persistent SRS resource set is configured, the connected NZP CSI-RS may be indicated through associatedCSI-RS in the SRS-ResourceSet, which is higher layer signaling. For non-codebook based transmission, the UE may not expect spatialRelationInfo, which is higher layer signaling for SRS resource, and associatedCSI-RS in SRS-ResourceSet, which is higher layer signaling, to be configured together.

When a plurality of SRS resources are configured, the UE can determine the precoder and transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. At this time, SRI may be indicated through a field SRS resource indicator in DCI or set through higher signaling srs-ResourceIndicator. Similar to the above-described codebook-based PUSCH transmission, when a UE receives SRI through DCI, the SRS resource indicated by the provided SRI corresponds to the SRI among SRS resources transmitted prior to the PDCCH including the corresponding SRI. It may mean an SRS resource. The UE may use one or a plurality of SRS resources for SRS transmission. The maximum number of SRS resources and the maximum number of SRS resources that can be simultaneously transmitted in the same symbol within one SRS resource set may be determined by UE capability reported by the UE to the base station. In this case, SRS resources transmitted simultaneously by the UE may occupy the same RB. The UE may configure one SRS port for each SRS resource. Only one SRS resource set in which the value of usage in SRS-ResourceSet, which is higher layer signaling, is set to 'nonCodebook' can be set, and up to four SRS resources for non-codebook based PUSCH transmission can be set.

The base station may transmit one NZP-CSI-RS associated with the SRS resource set to the terminal. The UE may calculate a precoder to be used when transmitting one or a plurality of SRS resources in an SRS resource set connected to the NZP-CSI-RS based on the measurement result when receiving the NZP-CSI-RS. The terminal may apply the calculated precoder when transmitting one or a plurality of SRS resources in the SRS resource set with usage set to 'nonCodebook' to the base station. The base station may select one or a plurality of SRS resources from among one or a plurality of received SRS resources. In this case, in non-codebook based PUSCH transmission, SRI may indicate an index capable of expressing a combination of one or a plurality of SRS resources. SRI may be included in DCI. In this case, the number of SRS resources indicated by the SRI transmitted by the base station may be the number of transmission layers of the PUSCH. The UE may transmit the PUSCH by applying a precoder applied to SRS resource transmission to each layer.

[PUSCH: Preparatory Course Hours]

Hereinafter, a description of the PUSCH preparation procedure time is described. When the base station schedules the UE to transmit the PUSCH using DCI format 0_0, 0_1, or 0_2, the UE may need time for preparing the PUSCH to transmit the PUSCH by applying the transmission method indicated through DCI (eg, transmission precoding method of SRS resource, number of transmission layers, spatial domain transmission filter). In NR, the PUSCH preparation process time is defined in consideration of this point. The PUSCH preparation process time of the UE may follow Equation 2 below.

In T _proc,2 of Equation 2, each variable may have the following meaning.

- N ₂ : This may mean the number of symbols determined according to UE processing capability 1 or 2 and numerology μ according to the capabilities of the UE. When reported as UE processing capability 1 according to the capability report of the UE, it may have the value of Table 29 below. When it is reported as UE processing capability 2 and it is configured through higher layer signaling that UE processing capability 2 can be used, it may have the value of Table 30.

-d _2,1 : When all resource elements of the first OFDM symbol of PUSCH transmission are set to consist of only DM-RS, this may mean the number of symbols set to 0. If the resource elements of the first OFDM symbol of PUSCH transmission are not all composed of DM-RS, this may mean the number of symbols determined as 1.

: 64-

:64

- μ: or Among them, T _proc,2 may follow a value that becomes larger. denotes the numerology of the downlink through which the PDCCH including the DCI scheduling the PUSCH is transmitted, may mean the numerology of the uplink through which the PUSCH is transmitted.

- T _c : can have a value of , can be

-d _2,2 : When the DCI scheduling the PUSCH indicates BWP switching, the BWP switching time may be followed., When the DCI scheduling the PUSCH does not indicate BWP switching, it may be 0.

- d ₂ : When PUCCH, PUSCH having a high priority index, and OFDM symbols of a PUCCH having a low priority index overlap in time, the value of d ₂ of the PUSCH having a high priority index may be used. Otherwise, d ₂ may be zero.

- T _ext : If the UE uses the shared spectrum channel access method, the UE can calculate T _ext and apply it to the PUSCH preparation process time. Otherwise, T _ext may be assumed to be zero.

- T _switch : When an uplink switching interval is triggered, T _switch can be assumed to be a switching interval time. Otherwise, it may be assumed to be 0.

When the base station and the UE consider the time axis resource mapping information of the PUSCH scheduled through DCI and the effect of timing advance (TA) between uplink and downlink, the PUSCH preparation process time is insufficient if the first symbol of the PUSCH starts earlier than the first uplink symbol that the CP starts after T _proc,2 from the last symbol of the PDCCH including the DCI for which the PUSCH is scheduled. If not, the base station and the terminal may determine that the PUSCH preparation process time is sufficient. The UE may transmit the PUSCH only when the PUSCH preparation process time is sufficient. When the PUSCH preparation process time is not sufficient, the UE may ignore the DCI for scheduling the PUSCH.

[PUSCH: related to repetitive transmission]

Hereinafter, a detailed description of repeated transmission of an uplink data channel in a 5G system will be described. In the 5G system, two types (eg, PUSCH repeated transmission type A and PUSCH repeated transmission type B) can be supported as a method of repeated transmission of an uplink data channel. The UE may be configured with either PUSCH repeated transmission type A or B through higher layer signaling.

PUSCH repetitive transmission type A

- As described above, the symbol length of an uplink data channel and the position of a start symbol can be determined by a time domain resource allocation method within one slot. The base station may notify the terminal of the number of repeated transmissions through higher layer signaling (eg, RRC signaling) or L1 signaling (eg, DCI).

- The terminal may repeatedly transmit an uplink data channel having the same length and start symbol in consecutive slots based on the number of repeated transmissions received from the base station. In this case, when at least one symbol of a slot configured as downlink by the base station or an uplink data channel symbol configured by the terminal is set to downlink, the terminal may omit transmission of the uplink data channel, but may count the number of repeated transmissions of the uplink data channel.

PUSCH repetitive transmission type B

- As described above, the start symbol and length of an uplink data channel can be determined in one slot using a time domain resource allocation method. The base station may notify the terminal of the number of repetitions of repeated transmissions through higher layer signaling (eg, RRC signaling) or L1 signaling (eg, DCI).

- The nominal repetition of the uplink data channel can be determined as follows based on the start symbol and the length of the uplink data channel configured first. The slot where the nth nominal repetition starts is The symbol given by and starting in that slot is can be given by The slot where the nth nominal repetition ends is The symbol given by and ending in that slot is can be given by Here, n = 0, ..., may be numberofrepetitions-1. S may indicate a start symbol of a configured uplink data channel. L may represent the symbol length of the configured uplink data channel. may indicate a slot in which PUSCH transmission starts. It can indicate the number of symbols per slot.

- The UE may determine an invalid symbol for PUSCH repeated transmission type B. A symbol configured for downlink by tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated may be determined as an invalid symbol for PUSCH repeated transmission type B. Additionally, an invalid symbol can be set in a higher layer parameter (e.g. InvalidSymbolPattern). A higher layer parameter (e.g. InvalidSymbolPattern) can provide a symbol level bitmap spanning one slot or two slots and an invalid symbol can be set. 1 in the bitmap may indicate an invalid symbol. Additionally, the period and pattern of the bitmap can be set through a higher layer parameter (eg, periodicityAndPattern). If an upper layer parameter (eg, InvalidSymbolPattern) is set and the InvalidSymbolPatternIndicator-ForDCIFormat0_1 or InvalidSymbolPatternIndicator-ForDCIFormat0_2 parameter indicates 1, the terminal may apply an invalid symbol pattern. If the InvalidSymbolPatternIndicator-ForDCIFormat0_1 or InvalidSymbolPatternIndicator-ForDCIFormat0_2 parameter indicates 0, the terminal may not apply the invalid symbol pattern. If a higher layer parameter (eg, InvalidSymbolPattern) is set and the InvalidSymbolPatternIndicator-ForDCIFormat0_1 or InvalidSymbolPatternIndicator-ForDCIFormat0_2 parameter is not set, the terminal may apply an invalid symbol pattern.

After the invalid symbol is determined, for each nominal repetition, the terminal may consider symbols other than the invalid symbol as valid symbols. If more than one valid symbol is included in each nominal repetition, the nominal repetition may include one or more actual repetitions. Here, each actual repetition may include a contiguous set of valid symbols that can be used for PUSCH repeated transmission type B in one slot.

15 illustrates PUSCH repeated transmission type B in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 15, the terminal can set the start symbol S of the uplink data channel to 0, the length L of the uplink data channel to 14, and the number of repetition transmissions to 16. In this case, nominal repetition (1501) may appear in 16 consecutive slots. After that, the terminal may determine a symbol set as a downlink symbol in each nominal repetition (1501) as an invalid symbol. In addition, the terminal may determine symbols set to 1 in invalid symbol pattern 1502 as invalid symbols. In each nominal repetition, when valid symbols other than invalid symbols are composed of one or more consecutive symbols in one slot, the valid symbols may be set as actual repetition (1503) and transmitted.

In addition, for repeated PUSCH transmission, in NR Release 16, the following additional methods may be defined for UL grant-based PUSCH transmission and configured grant-based PUSCH transmission across slot boundaries.

- Method 1 (mini-slot level repetition): Through one UL grant, two or more repeated PUSCH transmissions may be scheduled within one slot or across the boundary of consecutive slots. Also, for method 1, time domain resource allocation information in DCI may indicate resources of first repeated transmission. In addition, time domain resource information of the remaining repeated transmissions may be determined according to time domain resource information of the first repeated transmission and an uplink or downlink direction determined for each symbol of each slot. Each repeated transmission may occupy contiguous symbols.

- Method 2 (multi-segment transmission): Two or more repeated PUSCH transmissions may be scheduled in consecutive slots through one UL grant. At this time, one transmission is indicated for each slot, and different start points or repetition lengths may be different for each transmission. Also, in method 2, time domain resource allocation information in DCI may indicate a start point and repetition length of all repeated transmissions. In addition, when repeated transmission is performed within a single slot through method 2, if there are several bundles of consecutive uplink symbols in the corresponding slot, each repeated transmission may be performed for each bundle of uplink symbols. If a bundle of consecutive uplink symbols exists uniquely in the corresponding slot, one repetition of PUSCH transmission may be performed according to the method defined in NR Release 15.

- Method 3: Two or more repeated PUSCH transmissions may be scheduled in consecutive slots through two or more UL grants. At this time, one transmission is indicated for each slot, and the n-th UL grant may be received before the PUSCH transmission scheduled for the n-1-th UL grant ends.

- Method 4: Through one UL grant or one configured grant, one or several PUSCH repeated transmissions can be supported within a single slot. Alternatively, two or more repeated PUSCH transmissions may be supported across the boundary of consecutive slots. The number of repetitions indicated by the base station to the terminal is only a nominal value, and the number of repeated PUSCH transmissions actually performed by the terminal may be greater than the nominal number of repetitions. Time domain resource allocation information within the DCI or within the configured grant may mean resources of the first repeated transmission indicated by the base station. Time domain resource information of the remaining repeated transmissions may be determined by referring to resource information of at least the first repeated transmission and uplink or downlink directions of symbols. When the time domain resource information of repeated transmission indicated by the base station spans a slot boundary or includes an uplink/downlink switching point, the repeated transmission may be divided into a plurality of repeated transmissions. In this case, one repeated transmission may be included for each uplink period in one slot.

[PUSCH: frequency hopping process]

Hereinafter, a detailed description of frequency hopping of an uplink data channel (PUSCH) in a 5G system will be described.

In 5G, as frequency hopping methods of uplink data channels, two methods can be supported for each PUSCH repeated transmission type. In PUSCH repeated transmission type A, intra-slot frequency hopping and inter-slot frequency hopping can be supported. In PUSCH repetition transmission type B, inter-repetition frequency hopping and inter-slot frequency hopping can be supported. However, according to various embodiments of the present disclosure, an example of frequency hopping support may not be limited to the above-described example.

The intra-slot frequency hopping method supported by PUSCH repetitive transmission type A may include a method in which the terminal changes and transmits allocated resources in the frequency domain by a set frequency offset in two hops within one slot. In intra-slot frequency hopping, the starting RB of each hop can be expressed through Equation 3.

In Equation 3, i = 0 and i = 1 may represent the first hop and the second hop, respectively. may indicate a starting RB in the UL BWP and may be calculated from a frequency resource allocation method. may indicate a frequency offset between two hops through a higher layer parameter. The number of symbols in the first hop is , and the number of symbols in the second hop is can be expressed as is the length of PUSCH transmission in one slot, and can be represented by the number of OFDM symbols.

The inter-slot frequency hopping method supported by USCH repetitive transmission types A and B may include a method in which the terminal changes and transmits allocated resources in the frequency domain by a set frequency offset for each slot. In Inter-slot frequency hopping A starting RB during a slot can be expressed through Equation 4.

In Equation 4, may indicate a current slot number in multi-slot PUSCH transmission. may indicate a starting RB in the UL BWP and may be calculated from a frequency resource allocation method. may indicate a frequency offset between two hops through a higher layer parameter.

The inter-repetition frequency hopping method supported by PUSCH repeated transmission type B may include a method of moving and transmitting resources allocated in the frequency domain for one or a plurality of actual repetitions within each nominal repetition by a set frequency offset. RB _start (n), which is an index of a start RB in the frequency domain for one or a plurality of actual repetitions within the n-th nominal repetition, may follow Equation 5 below.

In Equation 5, n may represent the index of nominal repetition. may indicate an RB offset between two hops through a higher layer parameter.

[Related to PUSCH transmission power]

Hereinafter, a detailed description of a method for determining transmit power of an uplink data channel in a 5G system will be described.

In the 5G system, transmit power of an uplink data channel may be determined through Equation 6.

Referring to Equation 6, j may mean a grant type of PUSCH. Specifically, j = 0 may mean a PUSCH grant for a random access response, and j = 1 may mean a configured grant. j {2,3,...J-1} may mean dynamic grant. May mean the maximum output power set in the UE for carrier f of support cell c for PUSCH transmission occasion i. is set as an upper layer parameter and higher layer settings and SRI (eg, in case of dynamic grant PUSCH), which can be determined It may be a parameter composed of the sum of may mean a bandwidth for resource allocation represented by the number of resource blocks for PUSCH PUSCH transmission occasion i. may mean a value determined according to a modulation coding scheme (MCS) and the type of information transmitted through the PUSCH (eg, whether UL-SCH is included or not, CSI is included, etc.). Is a value for compensating for pathloss and may mean a value that can be determined through higher layer configuration and SRS resource indicator (SRI) (eg, in case of dynamic grant PUSCH). may mean a downlink path loss estimate estimated by the UE through a reference signal having a reference signal index of q _d . The reference signal index q _d is through higher layer configuration and SRI (eg, in the case of configured grant PUSCH (type 2 configured grant PUSCH) based on ConfiguredGrantConfig that does not include dynamic grant PUSCH or higher layer configuration rrc-ConfiguredUplinkGrant) or higher layer configuration. It can be determined by the terminal. is a closed loop power adjustment value and can be supported by an accumulation method and an absolute method. When the upper layer parameter tpc-Accumulation is not set in the UE, a closed loop power adjustment value may be determined by an accumulation method. Is the sum of TPC command values for the closed loop index l received through DCI between the closed loop power adjustment value for the previous PUSCH transmission occasion ii ₀ and the time before K _PUSCH (ii ₀ )-1 symbols from the transmission start time of PUSCH transmission occasion ii ₀ and the time before K _PUSCH (i) symbols from the transmission start time of PUSCH transmission occasion i. can be determined by If the upper layer parameter tpc-Accumulation is set in the terminal, is the TPC command value for closed loop index l received through DCI can be determined by The closed loop index l may be set to 0 or 1 when the higher layer parameter twoPUSCH-PC-AdjustementStates is set in the UE, and the value may be determined through higher layer configuration and SRI (in case of dynamic grant PUSCH). TPC command field and TPC value in DCI according to Accumualtion method and Absolute method A mapping relationship of can be defined as shown in Table 31.

[uplink PTRS related]

The terminal may set phaseTrackingRS, which is a higher layer parameter for PTRS, on the higher layer parameter DMRS-UplinkConfig. When transmitting the PUSCH to the base station, the terminal may transmit a phase tracking reference signal (PTRS) for phase tracking on the uplink channel. The procedure for transmitting the UL PTRS by the UE may be determined according to whether or not transform precoding is performed during PUSCH transmission. When transform precoding is performed and the transformPrecoderEnabled area is set in the upper layer parameter PTRS-UplinkConfig, sampleDensity in the transformPrecoderEnabled area may indicate sample density thresholds indicated by N _RB0 to N _RB4 in Table 32. When transform precoding is performed and the transformPrecoderEnabled region is set in the upper layer parameter PTRS-UplinkConfig, the UE can determine the PT-RS group pattern for the scheduled resource N _RB according to Table 32. Additionally, if the transform precoder is applied to PUSCH transmission, the number of bits of the PTRS-DMRS association field for indicating association between PTRS and DMRS in DCI format 0_1 or 0_2 may be 0.

When transform precoding is not applied to PUSCH transmission and the upper layer parameter phaseTrackingRS is set, the UE may indicate N _RB0 to N _RB1 for frequencyDensity in the transformPrecoderDisabled region of the upper layer parameter PTRS-UplinkConfig, and ptrs-MCS ₁ to ptrs-MCS ₃ for timeDensity. The UE may determine the PT-RS density in the time domain (L _PT-RS ) and the PT-RS density (K _PT-RS ) in the frequency domain, as described in Tables 33-1 and 33-2, according to the MCS (l _MCS ) and RB (N _RB ) of the scheduled PUSCH. In Table 33-1, ptrs-MCS ₄ is not specified as an upper layer parameter, but the base station and the terminal can know that it is 29 or 28 according to the set MCS table.

If transform precoder is not applied to PUSCH transmission and PTRS-UplinkConfig is set, the base station may indicate a 2-bit 'PTRS-DMRS association' field to the terminal to indicate association between PTRS and DMRS in DCI format 0_1 or 0_2. The indicated 2-bit PTRS-DMRS association field can be applied to Table 34-1 or Table 34-2 according to the maximum number of PTRS ports set as maxNrofPorts in the upper layer parameter PTRS-UplinkConfig. If the maximum number of PTRS ports is 1, the terminal can determine the association between the PTRS and DMRS with 2 bits indicated in Table 34-1 and the PTRS-DMRS association field, and transmit the PTRS according to the determined association. If the maximum number of PTRS ports is 2, the terminal can determine the association between the PTRS and DMRS with 2 bits indicated in Table 34-2 and the PTRS-DMRS association field, and transmit the PTRS according to the determined association.

The DMRS ports in Tables 34-1 and 34-2 can be determined through the 'Antenna ports' area indicated by the same DCI as the DCI indicating the PTRS-DMRS association and the table determined by the higher layer parameter settings. When the transform precoder is not set as the upper setting of the PUSCH, dmrs-Type is set to 1 and maxLength is set to 2, and the rank of the PUSCH is 2, the terminal can determine the DMRS port through the table for 'Antenna port(s)' as shown in Table 35 and the bits indicated in the antenna ports area. In the case of supporting noncodebook-based PUSCH, the UE can determine the rank value by referring to the SRI region indicated by the same DCI as the DCI including the 'Antenna ports' region (ie, if the SRI region does not exist, Rank can be regarded as 1). If the rank supports the codebook-based PUSCH, the UE can determine the rank value by referring to the TPMI region indicated by the same DCI as the DCI including the 'Antenna ports' region. Table 35 is an example of the antenna port table referred to when configuring the PUSCH described above, but is not limited thereto, and when the PUSCH is configured with other parameters, the DMRS port can be determined according to the 'Antenna port' table according to the setting and bits of the 'Antenna ports' area indicated by DCI.

The 1 ^st scheduled DMRS to 4 ^th scheduled DMRS in Table 34-1 may be defined as values obtained by sequentially mapping bits in the 'Antenna ports' area of DCI and DMRS ports indicated in the 'antenna port' table according to higher layer settings. For example, when the bit of the 'Antenna ports' field of the DCI is 0001 and the DMRS port is determined by referring to Table 35, the scheduled DMRS port may be 0 and 1, and DMRS port 0 may be 1 ^st scheduled DMRS, and DMRS port 1 may be defined as 2 ^nd scheduled DMRS. The DMRS port determined by the 'antenna port' table according to the bits of the other 'Antenna ports' area and other upper layer settings can be similarly applied. The terminal can determine one DMRS port to associate with the PTRS port by referring to the bit indicated by the PTRS-DMRS association in the DCI among the DMRS ports defined above, and transmits the PTRS according to the determined DMRS port.

In Table 34-2, the DMRS port that shares PTRS port 0 and the DMRS port that shares PTRS port 1 can be defined according to codebook-based PUSCH transmission or non-codebook-based PUSCH transmission. When a UE transmits a PUSCH based on a partial-coherent or non-coherent codebook, uplink layers transmitted through PUSCH antenna ports 1000 and 1002 may be related to PTRS port 0, and uplink layers transmitted through PUSCH antenna ports 1001 and 1003 may be related to PTRS port 1. More specifically, if Layer 3: TPMI = 2 is selected for the Codebook -based PUSCH transmission, the first layer may be associated with PTRS port 0 because the first layer is transmitted to PUSCH antenna port 1000 and 1002, and the second layer can be transmitted to the PUSCH antenna port 1001, and the third Layer Since it is transmitted to the PUSCH antenna port 1002, the second and third layers may be associated with PTRS Port 1. Each of the three layers may mean a DMRS port. The DMRS port for the first layer corresponds to '1 ^st DMRS port which shares PTRS port 0' in Table 19-2, the DMRS port for the second layer corresponds to '1 ^st DMRS port which shares PTRS port 1' in Table 34-2, and the DMRS port for the third layer may correspond to '2 ^nd DMRS port which shares PTRS port 1' in Table 34-2. Similarly, the DMRS port associated with PTRS port 0 and the DMRS port associated with PTRS port 1 may be determined according to different numbers of layers and TPMI. When a UE transmits a PUSCH based on a non-codebook, a DMRS port associated with PTRS port 0 and a DMRS port associated with PTRS port 1 can be distinguished according to SRI and antenna ports indicated by DCI. More specifically, whether the SRS resource included in the SRS resource set whose usage is 'nonCodebook' is associated with PTRS port 0 or PTRS port 1 can be set through the upper layer parameter ptrs-PortIndex. The base station may indicate an SRS resource for non-codebook based PUSCH transmission as SRI. The port of each indicated SRS resource may be mapped one-to-one with each PUSCH DMRS port. The association between the PUSCH DMRS port and the PTRS port may be determined according to the upper layer parameter ptrs-PortIndex of the SRS resource mapped to the DMRS port. More specifically, when ptrs-PortIndex is set to n0, n0, n1, and n1 in SRS resources 1 to 4 included in an SRS resource set whose usage is nonCodebook, PUSCH is instructed to be transmitted through SRS resources 1, 2, and 4 as SRI, and DMRS ports 0, 1, and 2 are indicated as antenna ports, the ports of each SRS resource 1, 2, and 4 are assigned to DMRS ports 0, 1, and 2 can be mapped. And, according to the ptrs-PortIndex in the SRS resource, DMRS ports 0 and 1 may have a relationship with PTRS port 0, and DMRS port 2 may have a relationship with PTRS port 1. Therefore, in Table 19-2, DMRS port 0 corresponds to '1 ^st DMRS port which shares PTRS port 0', DMRS port 1 corresponds to '2 ^nd DMRS port which shares PTRS port 0', and DMRS port 2 corresponds to '1 ^st DMRS port which shares PTRS port 1'. Similarly, the DMRS port associated with PTRS port 0 and the DMRS port associated with PTRS port 1 may be determined according to a method of configuring ptrs-PortIndex in the SRS resource of a different pattern and a different SRI value. The terminal may determine the relationship between the DMRS port and the PTRS port as above for the two PTRS ports. The terminal may determine a DMRS port to be associated with PTRS port 0 by referring to the MSB bit of the PTRS-DMRS association among a plurality of DMRS ports associated with each PTRS port. The UE may transmit PTRS by determining a DMRS port to be associated with PTRS port 1 by referring to the LSB bit.

[Regarding device ability reporting]

In the LTE and NR systems, the terminal may perform a procedure for reporting the capability supported by the terminal to the corresponding base station while connected to the serving base station. Hereinafter, this is referred to as a UE capability report.

The base station may transmit a UE capability inquiry message requesting a capability report to a UE in a connected state. The UE capability query message may include a UE capability request for each radio access technology (RAT) type of the base station. The UE capability request for each RAT type may include supported frequency band combination information. In addition, the UE capability inquiry message may include a request for UE capability for each RAT type through one RRC message container transmitted by the base station. The base station may include a terminal capability inquiry message including a terminal capability request for each RAT type multiple times and transmit the message to the terminal. That is, the UE capability inquiry is repeated multiple times within one message, and the UE may configure and report a UE capability information message corresponding to the UE capability information message multiple times. In the next-generation mobile communication system, it is possible to request UE capability for multi-RAT dual connectivity (MR-DC) including NR, LTE, and E-UTRA-NR dual connectivity (EN-DC). In addition, the terminal capability query message may be generally transmitted initially after the terminal is connected to the base station, but the base station may request it under any conditions when necessary.

According to an embodiment, a UE receiving a UE capability report request from a base station may configure UE capability according to RAT type and band information requested from the base station. A method for a UE to configure UE capabilities in the NR system is as follows.

One. When the terminal receives a list of LTE and/or NR bands from the base station as a UE capability request, the terminal may configure a band combination (BC) for EN-DC and NR stand alone (SA). That is, the terminal may configure BC candidate lists for the EN-DC and NR SAs based on the bands requested by the base station through FreqBandList. Also, bands may have priority in the order described in FreqBandList.

2. When the base station requests UE capability reporting by setting the 'eutra-nr-only' flag or the 'eutra' flag in the UE capability inquiry message, the terminal may completely remove those for NR SA BCs from the candidate list of the configured BCs. This operation may occur only when the LTE base station (eNB) requests the 'eutra' capability.

3. The terminal may remove fallback BCs from the configured BC candidate list. Here, the fallback BC may mean a BC obtained by removing a band corresponding to at least one SCell from any BC, and since the BC before removing the band corresponding to at least one SCell may already cover the fallback BC, it can be omitted. This step can also be applied in MR-DC (ie LTE bands can also be applied). BCs remaining after this step may be the final 'candidate BC list'.

4. The terminal can select BCs to be reported by selecting BCs suitable for the requested RAT type from the final 'candidate BC list'. In this step, the terminal can configure the supportedBandCombinationList in a predetermined order. That is, the UE may configure BC and UE capabilities to be reported according to the order of preset rat-Type (nr -> eutra-nr -> eutra). In addition, the terminal configures featureSetCombination for the configured supportedBandCombinationList, and configures a list of 'candidate feature set combinations' from the list of candidate BCs from which the list for fallback BCs (ie, including capabilities of the same or lower level) is removed. 'Candidate feature set combination' includes both feature set combinations for NR and EUTRA-NR BC, and can be obtained from feature set combination of UE-NR-Capabilities and UE-MRDC-Capabilities containers.

5. In addition, if the requested rat Type is eutra-nr and has an effect, featureSetCombinations may be included in both containers of UE-MRDC-Capabilities and UE-NR-Capabilities. However, the feature set of NR can only be included in UE-NR-Capabilities.

After the terminal capabilities are configured, the terminal may transmit a terminal capability information message including the terminal capabilities to the base station. The base station may then perform appropriate scheduling and transmission/reception management for the corresponding terminal based on the terminal capability received from the terminal.

[CA/DC related]

16 illustrates a radio protocol structure of a base station and a terminal in single cell 1610, carrier aggregation 1620, and dual connectivity 1630 situations according to an embodiment of the present disclosure.

16, the radio protocol of the next-generation wireless communication system may include NR service data adaptation protocols 1625 and 1670 (SDAP), NR packet data convergence protocols 1630 and 1665 (PDCP), NR radio link control 1635 and 1660 (NR MAC), and NR medium access control 1640 and 1655 (MAC) layers in a terminal and an NR base station, respectively. However, according to various embodiments of the present disclosure, the wireless protocol is not limited to the above example and may include more or fewer layers. In the following description, each layer device may be understood as a functional block in charge of the corresponding layer.

Main functions of the NR SDAPs 1625 and 1670 may include some of the following functions. However, according to various embodiments of the present disclosure, it may not be limited to the described examples.

- Transfer of user plane data

- A mapping function between a QoS flow and a data bearer for uplink and downlink (mapping between a QoS flow and a DRB for both DL and UL)

- Marking function of QoS flow ID for uplink and downlink (marking QoS flow ID in both DL and UL packets)

- A function of mapping reflective QoS flow to data bearer for UL SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

With respect to the SDAP layer device, the UE may be set whether to use the header of the SDAP layer device or the function of the SDAP layer device for each PDCP layer device, each bearer, or each logical channel through an RRC message. In addition, when the SDAP header is set, the terminal can be instructed to update or reset mapping information for uplink and downlink QoS flows and data bearers through NAS QoS reflection setting 1-bit indicator (NAS reflective QoS) and AS QoS reflection setting 1-bit indicator (AS reflective QoS) in the SDAP header. The SDAP header may include QoS flow ID information indicating QoS. The QoS information may be used as data processing priority and scheduling information to support smooth service.

The main functions of the NR PDCPs 1630 and 1665 may include some of the following functions. However, according to various embodiments of the present disclosure, the main functions of the NR PDCP may not be limited to the described functions.

- Header compression and decompression: ROHC (robust header compression) only

- Transfer of user data

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- PDCP PDU reordering for reception

- Duplicate detection of lower layer SDUs

- Retransmission of PDCP SDUs

- Ciphering and deciphering

- Timer-based SDU discard in uplink.

The NR PDCP reordering function may refer to a function of reordering PDCP PDUs received from a lower layer in order based on a PDCP sequence number (SN), and may include a function of transmitting data to an upper layer in the rearranged order. Alternatively, the NR PDCP reordering function may include a function of immediately forwarding without considering the order or a function of reordering and recording lost PDCP PDUs. The NR PDCP reordering function may include a function of reporting the status of lost PDCP PDUs to the transmitting side or a function of requesting retransmission of lost PDCP PDUs.

The main functions of the NR RLCs 1635 and 1660 may include some of the following functions.

- Transfer of upper layer PDUs

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- ARQ function (Error Correction through ARQ)

- Concatenation, segmentation and reassembly of RLC SDUs

- Re-segmentation of RLC data PDUs

- Reordering of RLC data PDUs

- Duplicate detection

- Error detection function (Protocol error detection)

- RLC SDU discard function (RLC SDU discard)

- RLC re-establishment

In-sequence delivery of NR RLC may refer to a function of sequentially delivering RLC SDUs received from a lower layer to an upper layer. In-sequence delivery of NR RLC may include a function of reassembling and delivering one RLC SDU when it is divided into several RLC SDUs, or a function of rearranging received RLC PDUs based on an RLC sequence number (SN) or a PDCP sequence number (SN). The in-sequence delivery function of NR RLC may include a function of reordering and recording lost RLC PDUs, a function of reporting the status of lost RLC PDUs to the transmitter, or a function of requesting retransmission of lost RLC PDUs. In-sequence delivery of NR RLC may include a function of sequentially delivering only RLC SDUs prior to the lost RLC SDU to the upper layer when there is a lost RLC SDU, or a function of sequentially delivering all RLC SDUs received before the timer starts if a predetermined timer expires even if there is a lost RLC SDU to the upper layer. In-sequence delivery of the NR RLC device may include a function of sequentially delivering all RLC SDUs received so far to a higher layer when a predetermined timer expires even if there is a lost RLC SDU. The in-sequence delivery function of the NR RLC device processes RLC PDUs in the order in which they are received (i.e., in the order of arrival regardless of the sequence number or sequence number) and delivers them to the PDCP device out of sequence (Out-of sequence delivery). In the case of a segment, it may include a function of receiving segments stored in a buffer or to be received later, reconstructing them into one complete RLC PDU, processing them, and delivering them to the PDCP device. The NR RLC layer may not include a concatenation function, and the concatenation function may be performed in the NR MAC layer or replaced with a multiplexing function of the NR MAC layer.

Out-of-sequence delivery of NR RLC may refer to a function of immediately delivering RLC SDUs received from a lower layer to a higher layer regardless of order. The out-of-sequence delivery function of NR RLC may include a function of reassembling and delivering an RLC SDU when one RLC SDU is originally divided into several RLC SDUs, or a function of storing the RLC SNs or PDCP SNs of received RLC PDUs and arranging them in order to record lost RLC PDUs.

The NR MACs 1640 and 1655 may be connected to several NR RLC layer devices configured in one terminal, and the main functions of the NR MAC may include some of the following functions. However, according to various embodiments of the present disclosure, the main functions included in the NR MAC may not be limited to the described functions.

- Mapping between logical channels and transport channels

- Multiplexing/demultiplexing of MAC SDUs

- Scheduling information reporting

- HARQ function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification

- Transport format selection

- Padding function (Padding)

The NR PHY layers 1645 and 1650 may channel-code and modulate higher-layer data, convert them into OFDM symbols, and transmit them through a radio channel. The NR PHY layer may demodulate OFDM symbols received through a radio channel, perform channel decoding, and transmit the results to a higher layer.

The detailed structure of the radio protocol structure may be variously changed according to a carrier (or cell) operating method. As an example, when a base station transmits data to a terminal based on a single carrier (or cell), the base station and the terminal may use a protocol structure having a single structure for each layer, as shown by reference number 1610 in FIG. 16 . On the other hand, when the base station transmits data to the terminal based on CA (carrier aggregation) using multiple carriers in a single TRP, the base station and the terminal have a single structure up to RLC as shown in reference number 1620, but multiplexing the PHY layer through the MAC layer. You can use a protocol structure. As another example, when a base station transmits data to a terminal based on dual connectivity (DC) using multiple carriers in multiple TRPs, the base station and the terminal have a single structure up to RLC as shown in reference number 1630, but through the MAC layer. A protocol structure for multiplexing the PHY layer can be used.

Referring to the descriptions related to PDCCH and beam configuration described above, it may be difficult to achieve required reliability in scenarios requiring high reliability, such as URLLC, since repeated PDCCH transmission is not currently supported in Rel-15 and Rel-16 NRs. The present disclosure provides a method for repeatedly transmitting a PDCCH through a plurality of transmission points (TRPs) to improve PDCCH reception reliability of a terminal. A specific method is specifically described through the embodiments disclosed below.

The present disclosure may be applied in at least one of FDD or TDD systems. However, this is only an example, and the present disclosure may also be applied to a cross division duplex system in which FDD and TDD systems are combined. Hereinafter, higher signaling (or higher layer signaling) in the present disclosure may be a method of transmitting a signal from a base station to a terminal using a downlink data channel of a physical layer or from a terminal to a base station using an uplink data channel of the physical layer. It may be referred to as RRC signaling, PDCP signaling, or medium access control (MAC control element, MAC CE).

Hereinafter, in the present disclosure, in determining whether or not to apply cooperative communication, a PDCCH(s) allocated to a PDSCH to which cooperative communication is applied has a specific format, or a PDCCH(s) allocated to a PDSCH to which cooperative communication is applied includes a specific indicator indicating whether or not cooperative communication is applied, or PDCCH(s) allocated to a PDSCH to which cooperative communication is applied is scrambled with a specific RNTI, or assumes cooperative communication in a specific interval indicated by a higher layer. can Hereinafter, for convenience of explanation, a case in which a UE receives a PDSCH to which cooperative communication is applied based on conditions similar to the above may be referred to as a non-coherent joint transmission (NC-JT) case.

Hereinafter, in the present disclosure, determining the priority between A and B selects a higher priority according to a predetermined priority rule and performs a corresponding operation or lower priority. It may be variously referred to as omitting or dropping.

Hereinafter, in the present disclosure, the above examples are described through a plurality of embodiments, but these are not independent, and one or more embodiments may be applied simultaneously or in combination.

According to various embodiments of the present disclosure, it is possible to improve the performance of uplink, which has lower performance than downlink, in terms of throughput, etc., and to improve uplink support equipment that is larger than general mobile terminals (e.g., customer premise equipment (CPE), fixed wireless access (FWA), etc.). In addition, for this purpose, it may be necessary to improve the PUSCH transmission technique so that a larger number of uplink antennas (eg, up to 8 or more) can be supported for uplink introduced up to Rel-17. Hereinafter, eight uplink antennas are described as an example for convenience of explanation, but it is obvious that the examples of the present invention are also applied to a larger number of uplink antennas.

When supporting codebook-based PUSCH using 8 uplink antenna ports, the codebook of 4 antenna ports may be reinforced or the introduction of a new type of codebook may be considered. In addition, the number and combination of antennas capable of coherent transmission may be considered according to the antenna implementation of the UE.

In addition, when codebook-based PUSCH and noncodebook-based PUSCH support 8 uplink antenna ports and support more than 4 layers, the 4 layers introduced up to Rel-17 (i.e., 4 PUSCH DMRS ports). Reinforcement of the PTRS-DMRS association method may be required. According to various embodiments of the present disclosure, a method of constructing a codebook for codebook-based PUSCH support considering 8 uplink antenna ports and a PTRS-DMRS association method in case of supporting 8 uplink antenna ports. The operation of the UE is specifically disclosed.

For convenience of description, various embodiments of the present disclosure are described by integrating a cell, panel, beam, and/or transmission direction that can be distinguished through upper layer/L1 parameters such as TCI state and spatial relation information, or indicators such as cell ID, TRP ID, and panel ID as a transmission reception point (TRP). Therefore, in actual application, TRP may be appropriately replaced with one of the above terms.

Hereinafter, in the present disclosure, in determining whether cooperative communication is applied, a PDCCH(s) allocating a PDSCH to which cooperative communication is applied has a specific format, or a PDCCH(s) allocating a PDSCH to which cooperative communication is applied includes a specific indicator indicating whether or not cooperative communication is applied, or PDCCH (s) allocating a PDSCH to which cooperative communication is applied is scrambled with a specific RNTI, or assumes cooperative communication in a specific interval indicated through higher layer signaling. methods can be used. For convenience of description below, a terminal receiving a PDSCH to which cooperative communication is applied based on conditions similar to the above may be referred to as an NC-JT case.

Hereinafter, in describing the present disclosure, higher layer signaling may be signaling corresponding to at least one or a combination of one or more of the following signaling. However, according to various embodiments of the present disclosure, higher layer signaling may not be limited to the described signaling.

- master information block (MIB)

- System information block (SIB) or SIB X (X=1, 2, ...)

- radio resource control (RRC)

- medium access control (MAC) control element (CE)

Also, L1 signaling may be signaling corresponding to at least one or a combination of one or more of signaling methods using the following physical layer channels or signaling. However, according to various embodiments of the present disclosure, L1 signaling may not be limited to the described signaling.

- physical downlink control channel (PDCCH)

- Downlink control information (DCI)

- UE-specific DCI

- group common DCI

- Common DCI

- Scheduling DCI (e.g. DCI used for the purpose of scheduling downlink or uplink data)

- Non-scheduling DCI (e.g., a DCI that is not intended to schedule downlink or uplink data)

- PUCCH (physical uplink control channel)

- Uplink control information (UCI)

Hereinafter, in the present disclosure, determining the priority between A and B selects a higher priority according to a predetermined priority rule and performs a corresponding operation or lower priority. It may be variously referred to as omitting or dropping.

Hereinafter, in the present disclosure, the above examples are described through a plurality of embodiments, but they are not independent, and one or more embodiments may be applied simultaneously or in combination.

<First Embodiment: Uplink Codebook Configuration Method for Supporting Codebook-based PUSCH Transmission with 8 Uplink Tx Antennas>

The first embodiment of the present disclosure may include a method of configuring an uplink codebook used by a terminal supporting 8 transmit antennas for uplink to transmit an uplink data signal. Eight transmit antennas for uplink may mean eight physical antennas, or a case in which eight or more (or less than eight) physical antennas of an actual terminal are configured with eight uplink transmission ports through antenna virtualization. However, the 8 transmit antennas for uplink according to various embodiments of the present disclosure are not limited thereto, and all cases that can be assumed as a terminal having 8 transmit antennas through other antenna configuration methods may be included. In addition, the case of having less than or more transmit antennas than 8 (eg, 6, 12, 16, etc.) may also be included in the embodiments of the present disclosure.

In NR Releases 15 to 17, up to four uplink antennas can be used for uplink data channel transmission. However, in a later NR release (eg, NR Release 18), in order to improve uplink transmission that has lower performance than downlink in terms of throughput, etc., uplink data channel transmission schemes using up to eight uplink antennas can be considered.

When the terminal transmits the uplink data channel (PUSCH) to the base station, as described above in the PUSCH transmission method related content, the PUSCH transmission method can be divided into 'codebook'-based PUSCH transmission and 'nonCodebook'-based PUSCH transmission. When the terminal performs PUSCH transmission based on 'codebook', the terminal can transmit SRS resource(s) that can be composed of a plurality of SRS ports (or can be composed of a single SRS port), and the base station can receive it. Thereafter, the base station selects one SRS resource from among a plurality of SRS resources (e.g., when receiving a plurality of SRS resources) based on the uplink channel information obtained through the received SRS resources to schedule the PUSCH. The SRI region in the DCI can be determined.

In addition, the base station may select a layer and a precoder of an uplink data channel based on the determined SRS resource to determine a TPMI region in the DCI scheduling the same PUSCH as the SRI region. Codebooks up to NR Release 17 considered the case of up to 4 uplink antennas. A row of a precoder indicated by TPMI may mean a transmit antenna (e.g., in [abcd] ^T , a is the value for the first transmit antenna, b is the value for the second transmit antenna, c is the value for the third transmit antenna, and d is the value for the fourth transmit antenna), and may consist of up to four rows. According to one embodiment, when up to 8 transmit antennas instead of up to 4 are used to support codebook-based uplink data channels (uplink control channels may also be included), a codebook capable of supporting up to 4 transmit antennas as well as a new codebook capable of supporting up to 8 transmit antennas may be required. Hereinafter, in the 1-1 and 1-2 embodiments, methods for constructing a codebook considering 8 uplink transmit antennas are described.

<Embodiment 1-1: How to extend uplink codebook to support 8 antennas>

According to an embodiment of the present disclosure, a method of extending an uplink codebook for supporting Rel-15 to Rel-17 codebook-based PUSCH transmission from up to 4 transmit antennas to up to 8 transmit antennas is described.

For uplink codebooks up to NR Release 17, the UE capability is reported to the base station to support one of 'fullCoherent', 'partialCoherent' or 'nonCoherent' according to the antenna coherency that the UE can support, and the base station sets the upper layer parameter 'codebookSubset' (or 'codebookSubsetDCI-0-2-r16') to the UE to indicate a subset of supported uplink codebooks based on the reported UE capability. can Here, 'fullyAndPartialAndNonCoherent' that can use the entire coherent codebook as a subset of codebooks, 'partialAndNonCoherent' that can use partial coherent or non-conherent codebooks, or 'nonCoherent' that can use only non-coherent codebooks. Can be set as the value of the upper layer parameter. When full coherent transmission is supported based on four uplink transmission antennas, the subset of indicated codebooks uses all four antennas (e.g., using a precoding matrix with four non-zero values in the column of the precoding matrix, which means a precoder for each layer. The precoding matrix for Releases 15 to 17 in the present disclosure is precoding matrices) may mean that a corresponding layer of the PUSCH is transmitted. A subset of the indicated codebooks, when partial coherent transmission is supported, can mean that a corresponding layer of the PUSCH is transmitted using two antennas capable of coherent transmission (e.g., using a precoding matrix having two non-zero values in a column of a precoding matrix indicating a precoder for each layer). A subset of the indicated codebooks, when non-coherent transmission is supported, may mean that antenna port selection for transmitting a corresponding layer of the PUSCH is supported using one antenna (e.g., using a precoding matrix having one non-zero value in a column of a precoding matrix indicating a precoder for each layer). At this time, as described in Clause 6.4D.4 of 3GPP standard document 38.101-1, the requirement for coherent uplink transmission is the relative power and phase error measured in a slot within a specific time window (time window, Time window in Table 36) from the most recently transmitted SRS to the same antenna port for different antenna ports and the values (relative power measured with the recently transmitted SRS) for coherent uplink transmission. and phase error) is less than or equal to the value defined in the standard document TS 38.101-1 as shown in Table 36, coherent uplink MIMO may be allowed.

According to an embodiment, when the difference value of the power and phase error between antenna ports within a specific time window is within an allowable value when compared with the value at the time of SRS transmission, the power and phase error between the ports are within an allowable value (e.g., When the power and phase error difference value characteristics between antenna ports are maintained), the corresponding antenna port may be considered to support coherent uplink transmission. The fact that the UE supports full coherent uplink transmission for four transmit antennas may mean that coherent transmission is possible for all four transmit antennas. Supporting partial coherent uplink transmission by a UE for four transmit antennas may mean that coherent transmission is possible for two antenna combinations composed of two transmit antennas, but support for coherent transmission cannot be guaranteed for two antenna ports that are not an antenna combination capable of coherent transmission (e.g., it does not mean that coherent transmission is impossible, but that the requirement for coherent uplink transmission within a specific time window cannot be guaranteed). In case of supporting codebook-based PUSCH in consideration of whether coherent transmission is supported between antenna ports, the UE can support a subset of the entire codebook. Here, the entire codebook may be defined as a combination of precoders considering characteristics of full, parital, and non-coherent transmission.

According to an embodiment of the present disclosure, when the number of uplink transmission antennas is increased from a maximum of 4 to 8, a codebook for supporting 8 antenna ports may be defined. According to an embodiment, in NR Releases 15 to 17, a codebook for uplink transmission may be defined based on antenna coherency that a UE can support.

If the UE can perform full coherent transmission through 8 uplink transmit antennas, an uplink codebook composed of 8x1 vectors can be defined as shown in Equation 7. However, according to various embodiments of the present disclosure, the 8x1 vector described below is only an example and is not limited thereto, and based on the number of antennas, less or more vectors (eg, 6x1 vectors, 12x1 vectors, 16x1 vectors) An uplink codebook composed of can be defined. In addition, according to various embodiments of the present disclosure, the parameters, configurations, etc. described below are described based on an 8x1 vector, but are not limited thereto, and the corresponding parameters and configurations can be applied based on the number of implemented antennas and vectors corresponding thereto.

Referring to Equation 7, each values are non-zero may be any value that prevents 8 elements of the vector from becoming 0. as an example may be one of 1, -1, j, -j.

According to an embodiment, when one layer is supported by eight transmit antennas, the base station may select one of precoding matrix candidates composed of one 8x1 vector. The base station may instruct the terminal with a precoding matrix through the TPMI included in the DCI for scheduling the codebook-based PUSCH. The signaling transmitted by the base station to indicate the precoding matrix to the UE is not limited to the above example, and may include any signaling (eg, higher layer parameter setting for CG PUSCH support, etc.) to indicate the precoding matrix. According to an embodiment, when two or more layers are supported by 8 transmit antennas, the base station may select one of 8x1 precoding matrix candidates composed of l 8x1 vectors of the number of corresponding layers. A base station may instruct a corresponding precoding matrix to a terminal through a TPMI included in a DCI for scheduling a codebook-based PUSCH. The signaling transmitted by the base station to indicate the precoding matrix to the UE is not limited to the above example, and may include any signaling (eg, higher layer parameter setting for CG PUSCH support, etc.) to indicate the precoding matrix. l 8x1 vectors corresponding to each column of the 8x l precoding matrix can be designed to have orthogonal characteristics. The number l of supported layers may support not only 4, which was supported up to NR Release 17, but also a value greater than 4 (eg, up to 8 layers). In order to support this, the base station can determine the capability that the UE can support layers greater than 4 by using the capability report of the UE. The base station may support uplink transmission using layers greater than 4 based on higher layer parameter settings (eg, maxRank setting of higher layer parameter PUSCH-Config). A UE capable of full coherent transmission can also support a precoding matrix for paritial coherent transmission or a precoding matrix for non-coherent transmission, which will be described later.

If the UE can support only non-coherent transmission through 8 uplink transmit antennas, an uplink codebook consisting of 8x1 vectors can be defined as shown in Equation 8 below.

Referring to Equation 8, only one of the values a, b, c, d, e, f, g, and h can be 1, and all other values must be 0.

In both cases where the UE supports only 1 layer or more than 2 layers with 8 transmit antennas, the base station may support the UE either by using a precoding matrix composed of 8x1 vectors defined in Equation 7 as in the above-described full coherent (e.g. when supporting 1 layer) or by using an 8x l precoding matrix composed of l 8x 1 vectors defined in Equation 7 (e.g. when supporting l layer). A terminal capable of supporting only non-coherent may not be supported by the precoding matrix for full coherent transmission described above and the precoding matrix for partial coherent transmission described later.

If the UE can support partial coherent transmission through 8 uplink transmit antennas, an uplink codebook composed of 8x1 vectors can be defined in consideration of the following situations.

[Situation 1] Case in which the UE can support coherent transmission between two antenna ports: Situation 1 is a case in which the UE can support coherent transmission for only two antenna port combinations among eight antenna ports. For example, among antenna ports 0 to 7, antenna ports {0, 4} can perform coherent transmission, and similarly, antenna port combinations {1,5}, {2, 6}, and {3, 7} can perform coherent transmission. This combination is only an example and is not limited to the above-mentioned combination, and any combination capable of coherent transmission of two out of eight antenna ports, such as {0, 1}, {2, 3}, {4, 5}, {6, 7}, etc. may correspond to situation 1. In the present disclosure, for convenience of description, it is assumed that antenna ports {0, 4}, {1,5}, {2, 6}, and {3, 7} are combinations capable of coherent transmission (meaning that various embodiments of the present disclosure are not limited to the described combination only). The design of a UE capable of coherent transmission of a combination of two antenna ports among eight antenna ports can be supported with complexity similar to that of an implementation for supporting partial coherent transmission consisting of a total of four antenna ports. According to an embodiment of the present disclosure, the number of antenna port combinations capable of full partial coherent transmission may increase and thus the overall design complexity may increase, but the assumption of a coherent antenna during PUSCH transmission may be implemented similarly to that described above. When coherent transmission is possible for antenna port combinations, an uplink codebook composed of 8x1 vectors can be defined as shown in Equation 9 below.

Referring to Equation 9, each values are non-zero may be any value that prevents 8 elements of the vector from becoming 0. as an example may be one of 1, -1, j, -j.

In both cases where the UE supports only 1 layer or more than 2 layers with 8 transmit antennas, the base station may support the UE either by using a precoding matrix composed of 8x1 vectors defined in Equation 7 as in the above-described full coherent (when one layer is supported) or by using an 8x 1 precoding matrix composed of l 8x 1 vectors defined in Equation 7 (eg, when l layers are supported).

A UE capable of partial coherent transmission can also support the precoding matrix for non-coherent transmission described above. In case 1, only the combination of two antennas supports coherent transmission, so the performance gain in terms of antenna diversity may be small compared to case 2, which supports four coherent transmissions described below.

[Situation 2] Case where the UE can support coherent transmission between 4 antenna ports: Situation 2 is a case where the UE can support coherent transmission for only 4 antenna port combinations among 8 antenna ports. For example, among antenna ports 0 to 7, antenna ports {0, 2, 4, 6} can perform coherent transmission, and similarly, coherent transmission can be performed for combinations of antenna ports {1, 3, 5, 7}. This combination is only an example, and is not limited to the above-mentioned combination, and any combination capable of coherent transmission of 4 out of 8 antenna ports, such as {0, 1, 2, 3}, {4, 5, 6, 7}, may correspond to situation 2. According to an embodiment of the present disclosure, for convenience of explanation, it is assumed that antenna ports {0, 2, 4, 6} and {1, 3, 5, 7} are combinations capable of coherent transmission (various embodiments of the present disclosure are not limited to the described combination). The fact that the terminal is designed so that coherent transmission can be performed by a combination of 4 antenna ports out of 8 antenna ports is compared to performing partial coherent transmission with 2 antenna ports out of 4 existing antenna ports. Implementation complexity increases, but a large diversity performance gain can be obtained. In this way, if coherent transmission is possible for antenna port combinations, an uplink codebook composed of 8x1 vectors can be defined as shown in Equation 10 below.

Referring to Equation 10, each values are non-zero may be any value that prevents 8 elements of the vector from becoming 0. as an example may be one of 1, -1, j, -j.

In both cases where the UE supports only 1 layer or more than 2 layers with 8 transmit antennas, the base station may support the UE by using a precoding matrix composed of 8x1 vectors defined in Equation 7 as in the above-described full coherent (e.g., when one layer is supported) or by using an 8x l precoding matrix composed of l 8x 1 vectors defined in Equation 7 (e.g., when l layers are supported).

A UE capable of partial coherent transmission can also support the precoding matrix for non-coherent transmission described above. In addition, partial coherent transmission supporting coherent transmission between two antenna ports may also be supported according to UE design.

[Situation 3] When coherent transmission can be supported by a combination that can consist of a different number of antenna ports rather than an antenna port combination consisting of the same number of antenna ports consisting of only two or four: Unlike situations 1 and 2, the terminal can be designed so that coherent transmission is possible between different numbers of antenna ports rather than between the same number of antenna combinations according to the antenna configuration method of the terminal. For example, two of the eight antenna ports can perform coherent transmission and the remaining six antenna ports can perform coherent transmission. Alternatively, a terminal that supports coherent transmission for other combinations such as 3 and 5 may be designed. In this case, a coherent type that can be supported may be newly defined for reporting UE capability between the base station and the UE, and as an example, a new reporting parameter for supporting a new coherent antenna such as patialCoh3_5 or paritlaCoh2_6 may be introduced. In this way, when the new terminal capability is reported to the base station by the terminal, the base station may schedule the PUSCH using a corresponding uplink codebook. Equation 11 below shows an example of an uplink codebook composed of 8x1 vectors when coherent transmission is possible through two antenna ports and six antenna ports, respectively.

Referring to Equation 11, each values are non-zero may be any value that prevents 8 elements of the vector from becoming 0. as an example may be one of 1, -1, j, -j.

In this way, a method such as situation 1 may also be supported according to an antenna implementation method of a terminal supporting a new type of partial coherent transmission. Alternatively, situation 2 or other situations other than situation 1 may also be considered.

[Situation 4] Support for a plurality of partial coherent transmission methods that can be supported by the terminal among situations 1 to 3: Higher layer parameters can be newly defined to support a plurality of parital coherent transmission methods among situations 1 to 3 according to the antenna implementation method of the terminal. The UE may add a new partialCoherent assumption in addition to the conventional nonCoherent, partialCoherent, and fullCoherent assumptions to the UE capability report transmitted to the BS. For example, the UE may add partialCoherent2, partialCoherent4, or the aforementioned patialCoh3_5 or paritlaCoh2_6 to the UE capability report. The terminal may report one or a plurality of new terminal capabilities to the base station. Or, such as partialCoherent2_4, it may be defined so that coherent transmission for two antenna ports and coherent transmission for four antenna ports are possible can be reported as one UE reporting parameter. Thereafter, the base station can set a supported codebook subset, such as Partial2AndNonCoherent, Partial4AndNonCoherent , or Partial4AndPartial2AndNonCoherent , as codebookSubset when setting higher layer parameters related to PUSCH transmission based on the UE capability report reported by the UE. This is just one example, and various combinations such as FullyAndPartial2AndNonCoherent can be considered.

<Embodiment 1-2: How to configure an uplink codebook for 8 antennas in two stages considering polarization>

According to an embodiment of the present disclosure, in the 1st and 2nd embodiments, a method of constructing an uplink codebook for supporting 8 antennas consisting of two steps in consideration of polarization is described in detail.

In order to construct a codebook for 8 antennas, an example of an uplink codebook composed of 8x1 vectors in the case of considering the co-phase term as shown in Equation 12 can be shown.

Referring to Equation 12, is a vector that can include non-zero coefficients, and at least one of coefficients a, b, c, and d, or some or all of coefficients can be a non-zero value. Similar to the above examples It may be expressed in the form of and may be one of 0, 1, -1, j, and -j, but the case where all are 0 may be excluded. constructed in this way may be the same as or similar to the vectors for supporting 4 antenna ports used in NR Releases 15 to 17. Then, the co-phase term considering polarization between antennas An 8x1 vector can be constructed using

When the UE supports only 1 layer with 8 transmit antennas or supports 2 or more layers, the 8x1 vector defined in Equation 7 is the same as in the above-mentioned situations in the above-described embodiment 1-1. The base station can support the terminal using a precoding matrix composed of (eg, when one layer is supported) or using an 8x l precoding matrix composed of l 8x1 vectors defined in Equation 7 (when l layers are supported).

<Embodiment 2: Method for determining correlation between PTRS and DMRS to support codebook-based PUSCH transmission with 8 uplink transmit antennas>

According to an embodiment of the present disclosure, a specific method of associating an uplink PTRS with a PUSCH DMRS when supporting a codebook for supporting 8 uplink transmit antennas is described.

As described above in the first embodiment, depending on the case where the codebook for supporting 8 uplink transmission antennas is configured as in the 1-1 embodiment and the 1-2 embodiment, a method for determining the association between PTRS and DMRS can be considered.

<Embodiment 2-1: Method for determining correlation between PTRS-DMRS when using extended uplink codebook to support 8 transmit antennas>

In Embodiment 2-1 of the present disclosure, when the existing codebook for 4 uplink transmissions is extended for transmission of 8 uplink antennas like in Embodiment 1-1, the correlation between PTRS and DMRS of PUSCH is determined. A specific method for determining is described.

When codebook-based PUSCH is supported, when the codebook subset is non-coherent or partial coherent, the base station can indicate the DMRS port information to which the PTRS port is associated through predefined rules for the association between PTRS and DMRS and the PTRS-DMRS association field included in the DCI. When the terminal transmits a PTRS, the PUSCH DMRS, which is the basis of transmission, is indicated, so that more accurate uplink data reception can be performed through phase estimation and phase error correction using the DMRS and the PTRS included in the PUSCH received by the base station together. As described above, when the number of PTRS ports is two and codebook-based PUSCH is transmitted, the uplink layers transmitted through PUSCH antenna ports 1000 and 1002 are related to PTRS port 0, and the uplink layer transmitted through PUSCH antenna ports 1001 and 1003 may be related to PTRS port 1. Here, an antenna port may be defined as a channel through which another symbol transmitted through the same antenna port may be inferred based on a channel through which a symbol transmitted through a specific antenna port passes through. That is, it may mean that different symbols transmitted through the same antenna port are transmitted through the same physical antenna. Based on the antenna port, a relationship between channels passed through symbols transmitted through the same antenna port with or without additional information (eg, statistical channel characteristics, etc.) can be inferred. The aforementioned PUSCH antenna ports 1000 to 1003 can be understood as logically indexed values to distinguish antenna ports through which PUSCH is actually transmitted. For example, for a partial antenna among 4 antenna ports, a base station and a UE define a rule in advance for a layer (e.g., a DMRS port) associated with PTRS, and based on this, the PTRS-DMRS association area included in the DCI is interpreted, and the UE determines the association between the PTRS and the DMRS and uses it for PUSCH transmission. On the other hand, when some antenna combinations among 8 antenna ports support partial coherent transmission capable of coherent transmission, the base station and the terminal may define rules in advance for a layer associated with PTRS according to situations 1 to 4 described above in the 1-1 embodiment. For convenience of explanation, it can be assumed that methods 1 and 2 support the same two PTRS ports as before.

[Method 1: When partial coherent transmission is supported in consideration of the case where coherent uplink transmission is possible between two antenna ports as in situation 1 of the 1-1 embodiment]

In NR Releases 15 to 17, layers transmitted through PUSCH ports 0 and 2 are PTRS port 0, and layers transmitted through PUSCH ports 1 and 3 are defined to be associated with PTRS port 1 by using a method in which coherent transmission is possible or partial coherent even in non-coherent cases. However, situation 1 can define a total of four antenna port groups capable of coherent uplink transmission (e.g., four antenna port groups such as {0, 4}, {1,5}, {2, 6}, {3, 7} can be considered). For the 4 antenna port groups, the base station and the terminal may determine rules in advance so that the layer transmitted through the n antenna port groups is associated with PTRS port 0 and the layer transmitted through the remaining 4-n antenna port groups is associated with PTRS port 1. As an example, the layers transmitted through the antenna port groups {0, 4} and {2, 6} are associated with PTRS port 0, and the layers transmitted through the antenna port groups {1, 5} and {3, 7} are associated with PTRS port 1. The base station and the terminal can determine. Alternatively, the base station and the UE may determine that the layer transmitted through the antenna port groups {0, 4}, {1, 5} is associated with PTRS port 0 (or PTRS port 1) and the layer transmitted through the antenna port group {2, 6}, {3, 7} is associated with PTRS port 1 (or PTRS port 0). However, according to various embodiments of the present disclosure, it is not limited to the above example, and any other combination may be considered. In addition to the aforementioned antenna port group, an antenna port group composed of other antennas may also determine a relationship with a PTRS port through a similar method.

[Method 2: When partial coherent transmission is supported in consideration of the case where coherent uplink transmission is possible between four antenna ports as in situation 2 of the 1-1 embodiment]

In situation 2, two antenna port groups capable of four coherent uplink transmissions can be distinguished. Therefore, the base station and the terminal can decide to associate two PTRS ports with each antenna port group. For example, if an antenna port group capable of coherent transmission is configured, such as {0, 2, 4, 6} or {1, 3, 5, 7}, a layer transmitted through {0, 2, 4, 6} may be associated with PTRS port 0 (or PTRS port 1), and a layer transmitted through {1, 3, 5, 7} may be associated with PTRS port 1 (or PTRS port 0). However, according to various embodiments of the present disclosure, it is not limited to the above example, and any other combination may be considered. In addition to the aforementioned antenna port group, an antenna port group composed of other antennas may also determine a relationship with a PTRS port through a similar method.

[Method 3: How to indicate an antenna port that shares a PTRS port]

The base station receives a report of the terminal's capability for coherent transmission for eight uplink antennas from the terminal, and based on this, can determine an antenna port that shares the PTRS port. According to an embodiment, an antenna port sharing a PTRS port may be determined based on an antenna port group composed of antenna pods capable of coherent transmission, or may be determined considering only individual antenna pods. The base station that determines the antenna port group (s) or antenna port (s) sharing the PTRS port shares the PTRS port to the terminal through a higher layer parameter (or indication through signaling such as MAC CE or DCI) Information on the antenna port can be set. As an example, the base station may configure an antenna port group that may be associated with PTRS port 0 by defining a new higher layer parameter sharingPTRS . Coherent is available only for two antenna ports on the terminal, and as shown in one example of the situation 1 of the first-one embodiment, it is assumed that the {0, 4}, {1,5}, {2, 6}, {3, 7} is composed of antenna port sets, {0,4} is set 1, {1, 5} is set 2, {2,6} Set 3, {3, 7} is set 4, which can be identified according to the rules defined by the base station and the terminal. These predefined rules may be defined to use one standard method, may be determined by adding a list to a higher layer configuration, or may be determined through other signaling methods. If sets 1 and 2 are set in the new upper layer parameter sharingPTRS and the number of uplink PTRS ports is set to 2, PTRS port 0 can be associated with layers transmitted in sets 1 and 2 according to rules defined in advance by the base station and the terminal, and layers transmitted in other sets can be associated with PTRS port 1. An antenna port that can be associated with PTRS port 0, which is not an antenna port group, in the upper layer parameter sharingPTRS may be set as a value of the corresponding area, and the terminal may recognize that the remaining antenna ports that are not set are associated with PTRS port 1.

In methods 1 to 3, the case of using two PTRS ports has been described. However, the number of PTRS ports greater than two may be introduced in a later NR release. In this case, the method described above in the 2-1 embodiment may be extended to a number of PTRS ports greater than two and used. As an example, if four antenna port groups such as {0, 4}, {1, 5}, {2, 6}, {3, 7} are considered for a UE capable of coherent transmission for two antennas, the layer transmitted through the first antenna group {0, 4} is PTRS port 0, the layer transmitted through the second antenna group {1, 5} is PTRS port 1, and the layer transmitted through the third antenna group {2, 6} is PTRS port 2 and The base station and the terminal can determine the layer transmitted through the antenna group {3,7} to be associated with PTRS port 3. However, according to various embodiments of the present disclosure, it is not limited to the above-described examples, and other mapping methods may be considered so that an association relationship between an antenna port or antenna port groups and a PTRS port can be established.

<Embodiment 2-2: Method for determining correlation between PTRS-DMRS when using uplink codebook for supporting 8 transmit antennas considering polarization>

In Embodiment 2-2 of the present disclosure, a specific method for determining an association between PTRS-DMRS in the case of using a codebook for supporting 8 transmit antennas in uplink considering polarization as in Embodiment 1-2 is described.

If the codebook is defined to support 8 transmit antennas using a co-phase term, the two PTRS ports can be associated with the corresponding DMRS ports through the following methods.

[Method 1: A layer transmitted through an antenna port configured with the same co-phase term shares the same PTRS port]

Method 1 can be used when transmitting through an antenna group for the same co-phase term during partial coherent transmission. In the case of transmitting an uplink codebook for supporting 8 transmit antennas as defined in Equation 12 in the 1-2 embodiment, the co-phase term According to , the first four antenna ports may be classified into the same co-phase group, and the subsequent four antenna ports may be classified into the same co-phase group. For two antenna groups classified according to the co-phase term, a layer transmitted as an antenna group for the first co-phase term may be associated with PTRS port 0. Similarly, a layer transmitted as an antenna group for the second co-phase term may be associated with PTRS port 1.

[Method 2: Layers transmitted through antenna ports composed of different co-phase terms share the same PTRS port]

Method 2 can be used when grouping and transmitting antennas for different co-phase terms during partial coherent transmission. For example, referring to Equation 12 in Embodiment 1-2, the first antenna port and the fifth antenna port have the same a value, but may be distinguished by different co-phase terms. As such, the UE can perform partial coherent transmission by defining this combination as an antenna group capable of coherent transmission. When two antenna ports are partially coherent transmitted considering one antenna port from each co-phase term, a method similar to Method 1 of the 2-1 embodiment may be applied. In this case, an association relationship with a PTRS port may be determined for an antenna group capable of a total of four partial coherent transmissions by considering one antenna port for each co-phase term. The base station and the terminal may define layers transmitted in n groups among four antenna groups capable of coherent transmission considering a co-phase term to be associated with PTRS port 0. The base station and the terminal may define layers transmitted in the remaining 4-n groups to be associated with PTRS port 1. As an example, four antenna groups capable of coherent transmission such as {0, 4}, {1, 5}, {2, 6}, and {3, 7} may be defined in consideration of the co-phase term. In this case, the base station and the terminal may define a layer transmitted through antenna ports {0, 4} or {1, 5} to be associated with PTRS port 0. The base station and the terminal may define a layer transmitted through antenna ports {2, 6} or {3, 7} to be associated with PTRS port 1. Here, it may be considered that the definition defined between the base station and the terminal is fixed on a standard basis. Alternatively, a new UE report and higher layer parameter may be introduced, and the base station may determine by setting the higher layer parameter to the UE based on the UE report of the UE. However, according to various embodiments of the present disclosure, it is not limited to the above-described example, and an antenna group capable of performing the above-described four coherent transmissions may be defined differently, and a combination of antenna port groups associated with PTRS port 0 or port 1 may also be considered.

<Third Embodiment: Method for Determining Association Relationship between PTRS and DMRS to Support Noncodebook-based PUSCH Transmission with 8 Uplink Tx Antennas>

The third embodiment of the present disclosure describes a specific method for determining an association between a PTRS port and a DMRS port of a PUSCH when noncodebook-based PUSCH transmission is supported with 8 uplink transmit antennas.

In NR Releases 15 to 17, when a UE transmits a noncodebook-based PUSCH, the DMRS port of the PUSCH associated with the PTRS port is an SRS resource set associated with PUSCH transmission, as described in the uplink PTRS related section (e.g., SRS resource set whose usage is 'nonCodebook'). It can be determined according to the setting of the SRS resource. As an example, the upper layer parameter ptrs-PortIndex for the first and second SRS resources among the four SRS resources configured in the SRS resource set may be set to 'n0'. This may mean that the two SRS resources have a relationship with PTRS port 0. Similarly, among the four SRS resources set in the SRS resource set, the upper layer parameter ptrs-PortIndex for the third and fourth SRS resources may be set to 'n1', which means that the two SRS resources have an association with PTRS port 1. Then, when the base station schedules the PUSCH through the DCI based on the SRS for the received noncodebook, the PTRS port associated with the SRS resource(s) indicated by the SRI in the DCI can be transmitted together during PUSCH transmission. At this time, each indicated SRS resource consists of one port, the PUSCH port for PUSCH transmission may be configured identically to the indicated SRS port, and the terminal may transmit the configured port.

Also, each PUSCH port may mean each layer for PUSCH transmission. When a plurality of associated layers are indicated for one PTRS port, the base station may indicate a DMRS port (layer) to which the PTRS port is associated through a PTRS-DMRS association field included in the same DCI as the DCI for scheduling the PUSCH. This may be a method of indicating an association between PTRS-DMRS for 4 SRS resources based on 4 transmit antennas, and an enhanced method may be required to support PUSCH transmission using 8 transmit antennas. In the case of supporting noncodebook-based PUSCH using 8 transmit antennas, the enhanced method may be configured differently according to the number of SRS resources for noncodebook purposes determined by higher layer settings. At this time, the number of SRS resources for noncodebook use may be the number of SRS resources included in one SRS resource set for noncodebook use or the total number of SRS resources included in two SRS resource sets for noncodebook use, similar to the prior art. Alternatively, if n SRS resource sets for noncodebook use are defined in a later NR release, the total number of SRS resources included in the total number of n SRS resource sets for noncodebook use may be considered. According to an embodiment, even if a plurality of SRS resource sets for noncodebook use are configured, only the number of SRS resources in one set may be considered. In the third embodiment of the present disclosure, it is assumed that the number of SRS resources for noncodebook-based PUSCH transmission to be currently supported is determined through arbitrary assumptions and settings. In this case, it is assumed that the number of SRS resources is 8. However, this does not mean that the method is limited only to the case where the number of SRS resources is 8, and may be applied to other cases by extending the method.

When setting the upper layer for 8 SRS resources, the base station can set ptrs-PortIndex to 'n0' or 'n1' for each SRS resource. At this time, the base station may set a value for ptrs-PortIndex of the SRS resource in consideration of the following method. When a base station establishes an association between an SRS and a PTRS port using the methods below, one SRS resource may be associated with one PTRS port.

[Method 1: Associate the same number of SRS resources with each PTRS port]

Method 1 may include a method of setting the same number of SRS resources associated with PTRS port 0 and PTRS port 1. According to one embodiment, when 8 SRS resources are included in an SRS resource set for one noncodebook, ptrs-PortIndex of 4 of them can be set to 'n0' so that they are associated with PTRS port 0, and the remaining 4 SRS resources can have their ptrs-PortIndex set to 'n1' to be associated with PTRS port 1. If the number of SRS resources in the SRS resource set is odd, the number of SRS resources associated with one of PTRS port 0 and PTRS port 1 may be more than one. For example, if the number of SRS resources is 7, 4 SRS resources may be associated with PTRS port 0 and 3 SRS resources may be associated with PTRS port 1.

[Method 2: How many SRS resources are associated with each PTRS port]

Unlike method 1 of the third embodiment, method 2 of the third embodiment differs from method 1 of the third embodiment (e.g., when the number of SRS resources is even or odd, one port is associated with one more SRS resource) of SRS resources. It may be a case where there is no restriction that it is associated with each PTRS port. ptrs-PortIndex can be set to 'n0' in the SRS resource so that n SRS resources are associated with PTRS port 0, and ptrs-PortIndex can be set to 'n1' for the remaining 8-n SRS resources. At this time, it can be expected that n is not set to 0 and the maximum number of SRS resources (eg, 8). As an example, through this method, the base station may configure PTRS port 0 to be associated with 6 SRS resources and PTRS port 1 to be associated with 2 SRS resources. This may be determined based on the base station receiving a new or existing terminal capability report from the terminal. A new or existing UE capability report that can be related to whether or not the UE can perform coherent transmission of an uplink transmission antenna (e.g., select one of full, partial, or non), or a UE report on an antenna group capable of new coherent transmission described above, or any UE capability report that can be associated with another UE's antenna implementation may correspond. According to an embodiment, the terminal may report new terminal capabilities to the base station in relation to PTRS port configuration. The base station may refer to the UE capability report and set the PTRS port associated with the SRS resource through ptrs-PortIndex in the upper layer parameter SRS-Resource.

<Embodiment 4: Method for Configuring Areas in Downlink Control Information According to PTRS-DMRS Relationship Determination when Supporting 8 Uplink Tx Antennas>

According to an embodiment of the present disclosure, when the PTRS-DMRS association method is reinforced to transmit 8 uplink antennas, a specific method of configuring a PTRS-DMRS association area included in downlink control information (DCI) is described.

In NR Releases 15 to 17, the number of bits of the PTRS-DMRS association field included in DCI is 0 bits (e.g., the case where the number of ranks (layers) supported is 1, DFT-s-OFDM is supported, or the upper layer parameter maxRank is set to 1) or 2 bits. In the case of supporting up to 8 layers (eg, DMRS ports) whose maximum number of supportable layers is greater than 4 by supporting 8 uplink antennas, the number of PTRS-DMRS association areas may need to be reinforced. According to various embodiments of the present disclosure, a case in which up to 8 layers are supported is assumed, and a method of configuring a PTRS-DMRS association area in a DCI area is described, but is not limited thereto, and is less than 8 (e.g., up to 6 layers) or greater than 8 (in this case, the number of uplink antennas supported by the terminal may also be greater than 8).

- When the number of supported PTRS ports is 1: When the number of supported PTRS ports is 1, the number of bits of the PTRS-DMRS association area can be configured so that one of the total 8 layers can be selected. That is, one DMRS port associated with a PTRS port among 8 DMRS ports can be indicated using 3 bits. Table 37 shows the meaning of code points for PTRS-DMRS association area interpretation that can be supported when the number of supported PTRS ports is 1 and can be supported by up to 8 layers.

- When the number of supported PTRS ports is 2: When the number of supported PTRS ports is 2, the first a bits for PTRS port 0 and the subsequent b bits for PTRS port 1 can be configured according to the maximum number of layers associated with each PTRS port (e.g., the number of layers associated with each PTRS port according to each antenna port group among all layers in the case of a codebook base, the number of layers associated with each PTRS port according to the upper layer setting in the SRS resource among all layers in the case of a noncodebook base). For example, as in Method 1 of the 2-1 embodiment, an antenna port group associated with two PTRS ports and a layer transmitted through the corresponding antenna port group may be considered. At this time, in the codebook for 8 layers, if 4 layers are transmitted to antenna port groups associated with PTRS port 0 and the remaining 4 layers are transmitted to antenna port groups associated with PTRS port 1, each PTRS port and DMRS may require 2 bits each to indicate the association relationship. For example, when configuring a PTRS-DMRS association area, the base station may indicate an association between PTRS port 0 and a PUSCH DMRS port (layer) that may be associated with the first 2 bits, and the base station may indicate an association relationship between PTRS port 1 and a PUSCH DMRS port (layer) that may be associated therewith. That is, the number of bits of the entire PTRS-DMRS association field can be a total of 4 bits, and the first 2 bits can be used for PTRS port 0 and the next 2 bits can be used for PTRS port 1. In the case of Codebook PUSCH, when the terminal interprets the corresponding PTRS-DMRS association field included in the DCI, the precoding matrix and layer information selected by the SRI and TPMI indicated by the same DCI are checked, and based on this, the PUSCH DMRS port associated with the two PTRS ports can be identified first. Then, when a plurality of DMRS ports can be associated with a PTRS port, the PUSCH port associated with the PTRS port is finally determined through the PTRS-DMRS association area, and based on this, the terminal transmits the PUSCH and PTRS to the base station. In the case of Noncodebook PUSCH, the number of bits may be determined according to the number of SRS resources associated with each PTRS port for 8 SRS resources. When two PTRS ports are associated with four SRS resources as in Method 1 of the third embodiment, the first 2 bits can be used for PTRS port 0 and the next 2 bits can be used for PTRS port 1. Table 38 shows the meaning of codepoints for interpreting the PTRS-DMRS association region when the number of layers (PUSCH ports) associated with the two PTRS ports is the same as 4, respectively.

If the number of layers (PUSCH ports) associated with two PTRS ports is not the same, the meaning of the codepoint for the PTRS-DMRS association area may be different. As an example, when the number of layers associated with PTRS port 0 is 6 and the number of layers associated with PTRS port 1 is 2, the interpretation method for the codepoint of each MSB and LSB may be different as shown in Table 39.

Referring to Table 39, 3-bit MSB may be used to determine a DMRS port associated with PTRS port 0 and 1-bit LSB may be used to determine a DMRS port associated with PTRS port 1. Similarly, if 2 layers are associated with PTRS port 0 and 6 layers are associated with PTRS port 1, 2 MSB codepoints may be used and 6 LSB codepoints may be used. In this case, when the total number of bits is 4 bits, a PTRS-DMRS association area having the same number of bits as in the previous case in which the same number of layers and two PTRS ports are associated can be used. However, according to various embodiments of the present disclosure, the number of MSB bits of the PTRS-DMRS association field for PTRS port 0 and the number of LSB bits of the PTRS-DMRS association field for PTRS port may vary depending on settings, etc.

- When the number of supported PTRS ports is P greater than 2: When a number of PTRS ports greater than 2 are supported, bits for P different PTRS-DMRS associations may be defined according to the number of layers associated with each PTRS port, and may be defined to form one PTRS-DMRS association area by collecting them. If the number of layers associated with the PTRS port p is L _p , the number of codepoints required to indicate this may be at least L _p . So if you calculate the number of bits to represent it Bits may be required. Therefore, the number of bits of the entire PTRS-DMRS association area is It can be expressed as The codepoint for n bits may be used to determine the DMRS port associated with PTRS port p. Table 40 is a table showing the meaning of codepoints in the PTRS-DMRS association area that can be configured when supporting P PTRS ports.

<Embodiment 5: Method for determining correlation between DMRS and PTRS-DMRS according to codewords when supporting 8 uplink transmit antennas>

According to an embodiment of the present disclosure, when 8 uplink transmission antennas are supported, when two (or two or more) codewords are configured to transmit a PUSCH, a DMRS and a PTRS-DMRS considering each codeword. A specific method for determining the association relationship is described.

As 8 uplink transmit antennas are supported, the UE may support two (or more than two) codewords, which were supported up to one codeword (CW) in NR Releases 15 to 17. At this time, a mapping relationship between each PUSCH layer and codewords may be determined. Each codeword may be transmitted through a mapped PUSCH layer. According to specific embodiments, a case in which a terminal supporting 8 uplink transmit antennas transmits two codewords in 8 layers and supports one or two PTRS ports is specifically described, but this is only an example, and is generalized to K codewords and P PTRS ports, and an association relationship between K codewords and P PTRS is defined, so that the PUSCH DMRS port to which the PTRS port is associated may be finally determined.

When two codewords and two PTRS ports are supported, each PTRS port may be associated with each codeword, and a PUSCH DMRS port associated with any PTRS port may be determined as one of a plurality of PUSCH DMRS ports for the associated codeword. As a specific example, when the first codeword is transmitted through layers 0, 1, 2, and 3 and the first codeword is associated with PTRS port 0, the PUSCH DMRS port that can be associated with PTRS port 0 can be one of the PUSCH DMRS ports for layers 0, 1, 2, and 3. When the second codeword is transmitted over layers 4, 5, 6, and 7 and the second codeword is associated with PTRS port 1, the PUSCH DMRS port that can be associated with PTRS port 1 can be one of the PUSCH DMRS ports for layers 4, 5, 6, and 7. A method of selecting one of the four candidates for each PTRS port may be determined according to the DCI-based PTRS-DMRS association area as described above. Alternatively, it may be a PUSCH DMRS port having the lowest index among candidates. When determined according to the DCI-based PTRS-DMRS association field, similar to the specific example of the above-described embodiment, the first two bits can be used to indicate one of four PUSCH DMRS ports that can be associated with PTRS port 0, and then the two bits can be used to indicate one of four PUSCH DMRS ports that can be associated with PTRS port 1. As another example, two PTRS ports may be associated with only one codeword, and two of a plurality of PUSCH DMRS ports for transmitting a layer for the associated codeword may be determined and associated with each PTRS port. In this case, codewords associated with the two PTRS ports may be determined based on scheduling information of a PUSCH transmitting each codeword. As an example, when a DCI scheduling a PUSCH for transmitting two codewords includes an MCS region for each codeword, a codeword scheduled with a higher MCS region value among the two MCSs may be determined. However, this is only an example, and is not limited thereto, and if the DCI scheduling the PUSCH for transmitting two codewords includes the MCS region for each codeword, the codeword scheduled with a lower MCS region value can be determined. Of course. According to an embodiment, if the two MCSs have the same value, it may be determined that the first codeword (or the second codeword) can be associated with the two PTRS ports. Two of the layers for transmitting codewords associated with the two PTRS ports may be determined to be associated with the two PTRS ports, and the base station may instruct the UE so that the PUSCH DMRS ports for the determined two layers may be associated with the two PTRS ports. In this case, as a method for indicating an association between a PUSCH DMRS port and a PTRS port, as described above, it may be determined according to a DCI-based PTRS-DMRS association area. Alternatively, the first two PUSCH DMRS ports having the lowest indices among the candidates may be used. Among the layers for one determined codeword, the layer that can be associated with each PTRS port may be determined according to the transmitting antenna port in the case of a codebook-based PUSCH as described above, or in the case of a noncodebook-based PUSCH. It may be determined according to the ptrs-PortIndex set in the upper layer parameter SRS-Resource. Alternatively, the base station and the terminal may set a rule in advance such that m layers among M multiple layers for the determined codeword are associated with PTRS port 0 and M m layers are associated with PTRS port 1. When the maximum number of supportable layers is set to transmit two codewords in 5 to 7 layers instead of 8, mapping between layers and codewords for PUSCH transmission may be the same as (or similar to) PDSCH layer-codeword mapping for receiving two codewords, and a PTRS-DMRS association area (e.g., the number of bits in the area, the number of bits in the area for each PTRS port, etc.) may be determined accordingly. Alternatively, a PTRS-DMRS association area fixed to a certain bit value (eg, 4 bits according to the above-described embodiments of the present disclosure) may be supported regardless of the maximum number of supportable layers.

When two codewords and one PTRS port are supported, a codeword associated with one PTRS port may be determined based on scheduling information of a PUSCH transmitting each codeword. For example, if a DCI scheduling a PUSCH for transmitting two codewords includes an MCS region for each codeword, a codeword scheduled with a higher MCS region value may be determined. However, this is only an example and is not limited thereto, and if the DCI scheduling the PUSCH for transmitting two codewords includes the MCS region for each codeword, the codeword scheduled with a lower MCS region value can be determined. Of course. Alternatively, if the two MCSs have the same value, it may be determined that the first codeword (or the second codeword) can be associated with the PTRS port. One of the layers for transmitting a codeword associated with one PTRS port may be determined to be associated with the PTRS port, and the base station may instruct the terminal so that the PUSCH DMRS port for the determined one layer may be associated with the PTRS port. At this time, as a method for indicating the association between the PUSCH DMRS port and the PTRS port, as described above, it may be determined according to the DCI-based PTRS-DMRS association area. Alternatively, the first PUSCH DMRS port having the lowest index among the candidates may be used.

17 illustrates an operation flow of a base station for configuring a PTRS and determining precoding based on a capability report of a terminal according to an embodiment of the present disclosure.

Referring to FIG. 17 , in step 1705, the base station may receive a terminal capability report from the terminal. The UE capability report received by the base station may include information on the antenna coherency of the UE and the like.

In step 1715, the base station may set higher layer parameters for supporting the terminal based on the terminal capability report reported by the terminal and transmit them to the terminal. The higher layer parameter set by the base station may include at least one of precoder subset information for uplink transmission, SRS resource set information, or information on an indicator of whether to support codebook-based PUSCH or noncodebook-based PUSCH. Higher layer parameters configured by the base station may include all higher layer parameters related to PUSCH transmission of the UE.

In step 1725, the base station may schedule the SRS transmitted by the terminal before performing PUSCH scheduling. The SRS transmitted by the terminal may have one purpose of codebook or nonCodebook. Scheduling performed by the base station can be performed by at least one of DCI-based aperiodic, semi-persistent, which performs periodic reporting based on activation, or periodic, which performs periodic reporting based on higher layer settings.

In step 1735, the base station may schedule the PUSCH based on the received SRS. The SRS transmitted by the terminal may have one purpose of codebook or nonCodebook. The scheduled PUSCH may be a dynamic grant PUSCH based on DCI format 0_1 or DCI format 0_2. DCI scheduling the PUSCH may include at least one of SRI, TPMI, antenna port area, or PTRS-DMRS association area.

In step 1745, the base station may receive the PUSCH and UL PTRS transmitted by the terminal. The base station may estimate the phase error using the PUSCH DMRS associated with the received UL PTRS. The base station may perform phase error correction using the estimated phase error.

18 illustrates an operation flow of a terminal for configuring a PTRS and determining precoding based on a capability report of the terminal according to an embodiment of the present disclosure.

Referring to FIG. 18, in step 1805, the terminal may transmit a terminal capability report to the base station. The UE capability report transmitted by the UE may include information such as antenna coherency of the UE.

In step 1815, the terminal may receive higher layer parameters transmitted by the base station. The higher layer parameter received by the UE may include at least one of precoder subset information for uplink transmission, SRS resource set information, or information on an indicator indicating whether to support codebook-based PUSCH or noncodebook-based PUSCH. Higher layer parameters received by the UE may include all higher layer parameters related to PUSCH transmission of the UE.

In step 1825, the terminal may receive an SRS scheduled from the base station and transmit the corresponding SRS to the base station. The SRS transmitted by the terminal may have one purpose of codebook or nonCodebook. Scheduling performed by the base station can be performed by at least one of DCI-based aperiodic, semi-persistent, which performs periodic reporting based on activation, or periodic, which periodically reports based on higher layer settings.

In step 1835, the UE may receive PUSCH scheduling. The scheduled PUSCH may be a dynamic grant PUSCH based on DCI format 0_1 or DCI format 0_2. DCI scheduling the PUSCH may include at least one of SRI, TPMI, antenna port area, or PTRS-DMRS association area.

In step 1845, the UE may transmit PUSCH and UL PTRS. The PUSCH and UL PTRS transmitted by the UE may be configured based on the DCI transmitted by the base station.

19 illustrates a configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 19 , a terminal may include a transceiver that refers to a receiver 1901 and a transmitter 1903, a memory (not shown), and a terminal processing unit 1905. The terminal processing unit 1905 may be at least one processor, and may also be referred to as a controller or a controller. Hereinafter, the terminal processing unit 1905 will be described as a processor. According to various embodiments of the present disclosure described above, a processor may control overall devices of a terminal so that the terminal may operate according to a combination of at least one embodiment. However, the components of the terminal are not limited to the above-described examples. For example, a terminal may include more or fewer components than the aforementioned components. In addition, the terminal receiving unit 1901, the terminal transmitting unit 1903, the terminal processing unit 1905, and the memory may be implemented as a single chip.

The transceivers 1901 and 1903 may transmit and receive signals to and from the base station. Here, the signal may include control information and data. To this end, the transceiver may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that amplifies a received signal with low noise and down-converts its frequency. However, this is only an example of the transceiver, and components of the transceiver are not limited to the RF transmitter and the RF receiver.

In addition, the transceiver may receive a signal through a wireless channel, output the signal to the processor, and transmit the signal output from the processor through the wireless channel.

The memory may store programs and data required for operation of the terminal. In addition, the memory may store control information or data included in signals transmitted and received by the terminal. The memory may include a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media. Also, there may be a plurality of memories, and instructions for performing the above-described communication method may be stored.

The terminal processing unit 1905 can control a series of processes so that the terminal can operate according to the above-described embodiment. There may be a plurality of processors, and the processor may perform a component control operation of the terminal by executing a program stored in a memory.

According to an embodiment of the present disclosure, the terminal processing unit 1905 transmits terminal capability report information to a base station, receives a higher layer parameter determined based on the terminal capability report information including information on coherency between antennas of the terminal from the base station, transmits a sounding reference signal (SRS) determined by the higher layer parameter to the base station, and schedules a physical uplink shared channel (PUSCH) determined based on the SRS. It may be configured to receive downlink control information (downlink control information) from the base station and transmit the PUSCH and uplink (UL) phase tracking reference signal (PTRS) to the base station.

According to an embodiment, the higher layer parameter may include at least one of information about a precoder subset for uplink transmission, information about an SRS resource set, or information about an indicator indicating whether codebook-based PUSCH or noncodebook-based PUSCH is supported.

20 illustrates a configuration of a base station in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 20 , a base station may include a transceiver that refers to a receiver 2001 and a transmitter 2003, a memory (not shown), and a base station processing unit 2005. The base station may include a communication interface (not shown) for wired or wireless communication with another base station through a backhaul link. Hereinafter, the base station processing unit 2005 will be described as a processor. The processor may be at least one processor, and may also be referred to as a controller or a control unit. According to various embodiments of the present disclosure described above, a processor may control overall devices of the base station so that the base station operates according to a combination of at least one embodiment. However, components of the base station are not limited to the above-described examples. For example, a base station may include more or fewer components than those described above. In addition, the base station receiving unit 2001, the base station transmitting unit 2003, the base station processing unit 2005, the memory, and the interface may be implemented in a single chip form.

The transceivers 2001 and 2003 may transmit and receive signals to and from the terminal. Here, the signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying the frequency of a transmitted signal, and an RF receiver for low-noise amplifying a received signal and down-converting the frequency. However, this is only an example of the transceiver, and components of the transceiver are not limited to the RF transmitter and the RF receiver.

Also, the transceiver may receive a signal through a wireless channel, output the signal to the processor, and transmit the signal output from the processor through the wireless channel.

The memory may store programs and data necessary for the operation of the base station. In addition, the memory may store control information or data included in signals transmitted and received by the base station. The memory may include a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media. Also, there may be a plurality of memories, and instructions for performing the above-described communication method may be stored.

The base station processing unit 2005 may control a series of processes so that the terminal can operate according to the above-described embodiment. There may be a plurality of processors, and the processors may perform component control operations of the terminal by executing programs stored in memory.

According to an embodiment of the present disclosure, the base station processing unit 2005 receives UE capability report information from a UE, transmits a higher layer parameter determined based on the UE capability report information including information on coherency between antennas of the UE to the UE, receives a sounding reference signal (SRS) determined by the higher layer parameter from the UE, and schedules a physical uplink shared channel (PUSCH) based on the SRS, DCI ( downlink control information), transmit the DCI to the terminal, and receive the PUSCH and uplink (UL) phase tracking reference signal (PTRS) from the terminal.

According to an embodiment, the base station processing unit 2005 configures an uplink codebook based on the UE capability report information, and further configures the higher layer parameter based on the configured uplink codebook. The uplink codebook may be composed of a precoding matrix including a plurality of 8x1 vectors for supporting precoding of 8 antennas.

According to an embodiment, the uplink codebook may be determined considering coherent between the 8 antennas or considering polarization of the 8 antennas.

According to an embodiment, the base station processing unit 2005 transmits the association relationship between the DMRS of the PUSCH transmitted through the antenna determined by the setting of the base station and the PTRS through DCI when the uplink codebook is determined considering the coherent between the 8 antennas, and when the uplink codebook is determined considering the polarization of the 8 antennas, the association relationship between the DMRS of the PUSCH transmitted through the antenna and the PTRS 8x It is determined based on the co-phase term of 1 vector, and when the PTRS is associated with the DMRS of a plurality of PUSCHs, it may be further configured to transmit additional information to the terminal.

According to an embodiment, an association between the DMRS of the PUSCH transmitted through the antenna and the PTRS may be determined based on an SRS resource set associated with the PUSCH transmission or based on a codeword.

According to an embodiment, the higher layer parameter may include at least one of information about a precoder subset for uplink transmission, information about an SRS resource set, or information about an indicator indicating whether codebook-based PUSCH or noncodebook-based PUSCH is supported.

According to an embodiment, the DCI for scheduling the PUSCH includes at least one of an information field for an SRS resource indicator (SRI), an information field for a transmission precoding matrix indicator (TPMI), an information field for an antenna port region, or an information field for a PTRS-demodulation reference signal (PTRS-DMRS) association relationship, and the size of the information field for the PTRS-DMRS association relationship may be determined according to the number of supported PTRS ports.

According to an embodiment, the base station processing unit 2005 may be further configured to estimate a phase error based on a PUSCH demodulation reference signal (DMRS) associated with the UL PTRS, and correct the phase error based on the estimated phase error.

According to an embodiment of the present disclosure, a method performed by a base station in a wireless communication system includes receiving UE capability report information from a UE, transmitting a higher layer parameter determined based on the UE capability report information including information on coherency between antennas of the UE to the UE, receiving a sounding reference signal (SRS) determined by the higher layer parameter from the UE, scheduling a physical uplink shared channel (PUSCH) based on the SRS, Determining downlink control information (DCI) to be used, transmitting the DCI to the terminal, and receiving the PUSCH and uplink (UL) phase tracking reference signal (PTRS) from the terminal.

According to an embodiment, the step of transmitting the higher layer parameter determined based on the UE capability report information to the UE comprises configuring an uplink codebook based on the UE capability report information, and determining the higher layer parameter based on the configured uplink codebook, and the uplink codebook may be composed of a precoding matrix including a plurality of 8x1 vectors for supporting precoding of 8 antennas.

According to an embodiment, the uplink codebook may be determined considering coherent between the 8 antennas or considering polarization of the 8 antennas.

According to an embodiment, when the uplink codebook is determined in consideration of coherent between the 8 antennas, transmitting the association relationship between the DMRS of the PUSCH transmitted through the antenna determined by the setting of the base station and the PTRS through DCI, when the uplink codebook is determined considering the polarization of the 8 antennas, the association relationship between the DMRS of the PUSCH transmitted through the antenna and the PTRS is based on the co-phase term of the 8x1 vector The method may further include determining, and transmitting additional information to the terminal when the PTRS is associated with a DMRS of a plurality of PUSCHs.

According to an embodiment, an association between the DMRS of the PUSCH transmitted through the antenna and the PTRS may be determined based on an SRS resource set associated with the PUSCH transmission or based on a codeword.

According to an embodiment, the higher layer parameter may include at least one of information about a precoder subset for uplink transmission, information about an SRS resource set, or information about an indicator indicating whether codebook-based PUSCH or noncodebook-based PUSCH is supported.

According to an embodiment, the DCI for scheduling the PUSCH includes at least one of an information field for an SRS resource indicator (SRI), an information field for a transmission precoding matrix indicator (TPMI), an information field for an antenna port region, or an information field for a PTRS-demodulation reference signal (PTRS-DMRS) association relationship, and the size of the information field for the PTRS-DMRS association relationship may be determined according to the number of supported PTRS ports.

According to an embodiment, the method may further include estimating a phase error based on a PUSCH demodulation reference signal (DMRS) associated with the UL PTRS, and correcting the phase error based on the estimated phase error.

According to an embodiment of the present disclosure, a method performed by a UE in a wireless communication system includes transmitting UE capability report information to a base station, receiving a higher layer parameter determined based on the UE capability report information including information on coherency between antennas of the UE from the base station, transmitting a sounding reference signal (SRS) determined by the higher layer parameter to the base station, scheduling a physical uplink shared channel (PUSCH) determined based on the SRS Receiving ringing downlink control information (DCI) from the base station, and transmitting the PUSCH and uplink (UL) phase tracking reference signal (PTRS) to the base station.

According to an embodiment, the higher layer parameter may include at least one of information about a precoder subset for uplink transmission, information about an SRS resource set, or information about an indicator indicating whether codebook-based PUSCH or noncodebook-based PUSCH is supported.

Methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented in software, a computer readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

Such programs (software modules, software) may include random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage; It can be stored on a magnetic cassette. Alternatively, it may be stored in a memory composed of a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

In addition, the program may be stored in an attachable storage device accessible through a communication network such as the Internet, an intranet, a local area network (LAN), a wide LAN (WLAN), or a storage area network (SAN), or a communication network composed of a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. In addition, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, components included in the invention are expressed in singular or plural numbers according to the specific embodiments presented. However, singular or plural expressions are selected appropriately for the presented situation for convenience of description, and the present disclosure is not limited to singular or plural components, and components expressed in plural numbers are singular, or even components expressed in the singular number may consist of a plurality.

On the other hand, the embodiments of the present disclosure disclosed in the present specification and drawings are only presented as specific examples to easily explain the technical content of the present disclosure and help understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other modifications based on the technical idea of the present disclosure are possible. In addition, each of the above embodiments can be operated in combination with each other as needed. For example, a base station and a terminal may be operated by combining parts of one embodiment of the present disclosure and another embodiment. For example, a base station and a terminal may be operated by combining parts of the first embodiment and the second embodiment of the present disclosure. In addition, although the above embodiments have been presented based on the FDD LTE system, other modifications based on the technical idea of the above embodiment may be implemented in other systems such as a TDD LTE system, 5G or NR system.

Meanwhile, the order of description in the drawings for explaining the method of the present disclosure does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

Alternatively, drawings describing the method of the present disclosure may omit some components and include only some components within a range that does not impair the essence of the present disclosure.

In addition, the method of the present disclosure may be executed by combining some or all of the contents included in each embodiment within a range that does not impair the essence of the present invention.

Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes, and the embodiments of the present disclosure are not limited to the disclosed embodiments. Those of ordinary skill in the art to which the present disclosure belongs will be able to understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present disclosure. The scope of the present disclosure is indicated by the claims to be described later rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts thereof should be construed as being included in the scope of the present disclosure.

Claims (20)

In a method performed by a base station in a wireless communication system,
Receiving terminal capability report information from a terminal;
Transmitting a higher layer parameter determined based on the UE capability report information including information on coherency between antennas of the UE to the UE;
Receiving, from the terminal, a sounding reference signal (SRS) determined by the higher layer parameter;
Based on the SRS, determining downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH);
Transmitting the DCI to the terminal; and
Receiving the PUSCH and uplink (UL) phase tracking reference signal (PTRS) from the terminal.
The method of claim 1,
Transmitting the upper layer parameter determined based on the terminal capability report information to the terminal,
Configuring an uplink codebook based on the UE capability report information; and
Based on the configured uplink codebook, further comprising determining the higher layer parameter,
The uplink codebook is composed of a precoding matrix including a plurality of 8x1 vectors for supporting precoding of 8 antennas.
The method of claim 2,
The uplink codebook,
A method determined by considering coherent between the 8 antennas or considering polarization of the 8 antennas.
The method of claim 3,
When the uplink codebook is determined in consideration of coherent between the eight antennas, transmitting an association between the PTRS and the DMRS of the PUSCH transmitted through the antenna determined by the setting of the base station through DCI;
When the uplink codebook is determined in consideration of the polarization of the 8 antennas, determining an association between the PTRS and the DMRS of the PUSCH transmitted through the antennas based on the co-phase term of the 8x1 vector; and
The method further comprising transmitting additional information to the terminal when the PTRS is associated with DMRS of a plurality of PUSCHs.
The method of claim 1,
The association relationship between the DMRS of the PUSCH transmitted through the antenna and the PTRS is determined based on an SRS resource set associated with the PUSCH transmission or determined based on a codeword.
The method of claim 1,
The upper layer parameter is,
A method including at least one of information about a precoder subset for uplink transmission, information about an SRS resource set, or information about an indicator indicating whether codebook-based PUSCH or noncodebook-based PUSCH is supported.
The method of claim 1,
DCI scheduling the PUSCH,
At least one of an information field for an SRS resource indicator (SRI), an information field for a transmission precoding matrix indicator (TPMI), information for an antenna port area, or an information field for a PTRS-demodulation reference signal (DMRS) association relationship,
The size of the information field for the PTRS-DMRS association is determined according to the number of supported PTRS ports.
The method of claim 1,
estimating a phase error based on a PUSCH demodulation reference signal (DMRS) associated with the UL PTRS; and
and correcting the phase error based on the estimated phase error.
In a method performed by a terminal in a wireless communication system,
Transmitting terminal capability report information to a base station;
Receiving, from a base station, a higher layer parameter determined based on the UE capability report information including information on coherence between antennas of the UE;
Transmitting, to the base station, a sounding reference signal (SRS) determined by the higher layer parameter;
Receiving downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH) determined based on the SRS from the base station; and
Transmitting the PUSCH and uplink (UL) phase tracking reference signal (PTRS) to the base station.
The method of claim 9,
The upper layer parameter is,
A method including at least one of information about a precoder subset for uplink transmission, information about an SRS resource set, or information about an indicator indicating whether codebook-based PUSCH or noncodebook-based PUSCH is supported.
In a base station device in a wireless communication system,
at least one transceiver; and
Includes at least one processor functionally coupled to the at least one transceiver,
The at least one processor,
Receiving, from the terminal, terminal capability report information;
Transmitting a higher layer parameter determined based on the UE capability report information including information on coherency between antennas of the UE to the UE;
Receiving a sounding reference signal (SRS) determined by the higher layer parameter from the terminal,
Based on the SRS, determine downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH),
Transmitting the DCI to the terminal, and
Device configured to receive the PUSCH and uplink (UL) phase tracking reference signal (PTRS) from the terminal.
The method of claim 11,
The at least one processor,
Based on the UE capability report information, configure an uplink codebook, and
Based on the configured uplink codebook, further configured to determine the higher layer parameter,
The uplink codebook is composed of a precoding matrix including a plurality of 8x1 vectors for supporting precoding of 8 antennas.
The method of claim 12,
The uplink codebook,
An apparatus determined in consideration of coherent between the eight antennas or polarization of the eight antennas.
The method of claim 13,
The at least one processor,
When the uplink codebook is determined in consideration of coherent between the 8 antennas, a correlation between the PTRS and the DMRS of the PUSCH transmitted through the antenna determined by the setting of the base station is transmitted through DCI,
When the uplink codebook is determined in consideration of the polarization of the 8 antennas, the association relationship between the DMRS of the PUSCH transmitted through the antennas and the PTRS is determined based on the co-phase term of the 8x1 vector, and
and to transmit additional information to the terminal when the PTRS is associated with a DMRS of a plurality of PUSCHs.
The method of claim 11,
The association relationship between the DMRS of the PUSCH transmitted through the antenna and the PTRS is determined based on an SRS resource set associated with the PUSCH transmission or determined based on a codeword.
The method of claim 11,
The upper layer parameter is,
A device including at least one of information about a precoder subset for uplink transmission, information about an SRS resource set, or information about an indicator indicating whether codebook-based PUSCH or noncodebook-based PUSCH is supported.
The method of claim 11,
DCI scheduling the PUSCH,
At least one of an information field for an SRS resource indicator (SRI), an information field for a transmission precoding matrix indicator (TPMI), information for an antenna port area, or an information field for a PTRS-demodulation reference signal (DMRS) association relationship,
The size of the information field for the PTRS-DMRS association is determined according to the number of supported PTRS ports.
The method of claim 11,
The at least one processor,
Estimating a phase error based on a PUSCH demodulation reference signal (DMRS) associated with the UL PTRS, and
and correct the phase error based on the estimated phase error.
In a terminal device in a wireless communication system,
at least one transceiver; and
Includes at least one processor functionally coupled to the at least one transceiver,
The at least one processor,
To the base station, transmits terminal capability report information;
Receiving from a base station a higher layer parameter determined based on the terminal capability report information including information on coherency between antennas of the terminal,
Transmitting a sounding reference signal (SRS) determined by the higher layer parameter to the base station,
receiving downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH) determined based on the SRS from the base station; and
An apparatus configured to transmit the PUSCH and uplink (UL) phase tracking reference signal (PTRS) to the base station.
The method of claim 19
The upper layer parameter is,
A device including at least one of information about a precoder subset for uplink transmission, information about an SRS resource set, or information about an indicator indicating whether codebook-based PUSCH or noncodebook-based PUSCH is supported.

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